-ability Look up -ability at Dictionary.com
word-forming element expressing ability, fitness, or capacity, from Latin -abilitas, forming nouns from adjectives ending in -abilis (see -able). Not etymologically related to ability, though popularly connected with it.
-able Look up -able at Dictionary.com
word-forming element expressing ability, capacity, fitness, from French, from Latin -ibilis, -abilis, forming adjectives from verbs, from PIE *-tro-, a suffix used to form nouns of instrument.

In Latin, infinitives in -are took -abilis, others -ibilis; in English, -able tends to be used with native (and other non-Latin) words, -ible with words of obvious Latin origin (but there are exceptions). The Latin suffix is not etymologically connected with able, but it long has been popularly associated with it, and this has contributed to its survival as a living suffix. It is related to the second syllable of rudder and saddle.
-acea Look up -acea at Dictionary.com
word-forming element denoting orders and classes in zoology, from Latin -acea, neuter plural of -aceus "belonging to, of the nature of" (enlarged from adjectival suffix -ax, genitive -acis); neuter plural because of a presumed animalia, a neuter plural noun. Thus, crustacea "shellfish" are *crustacea animalia "crusty animals." In botany, the suffix is -aceae, from the fem. plural of -aceus, with reference to Latin plantae, which is a fem. plural.
-aceous Look up -aceous at Dictionary.com
word-forming element denoting "belonging to, of the nature of," from Latin -aceus, enlarged form of adjectival suffix -ax (genitive -acis); see -acea. Especially in biology, "pertaining to X order of plants or animals."
-acious Look up -acious at Dictionary.com
adjectival word-forming element meaning "given to, inclined to, abounding in," from Latin -aci- (nominative -ax), noun ending used with verbal stems, + -ous.
-ad Look up -ad at Dictionary.com
word-forming element denoting collective numerals (Olympiad), plant families, and names of poems, from Greek -as (genitive -ados), a suffix forming fem. nouns; also used in fem. patronymics (Dryad, Naiad, also, in plural, Pleiades, Hyades).
-ade Look up -ade at Dictionary.com
word-forming element denoting an action or product of an action, from Latin -ata (source of French -ade, Spanish -ada, Italian -ata), fem. pp. ending used in forming nouns. A living prefix in French, from which many words have come into English (such as lemonade). Latin -atus, past participle suffix of verbs of the 1st conjugation also became -ade in French (Spanish -ado, Italian -ato) and came to be used as a suffix denoting persons or groups participating in an action (such as brigade, desperado).
-ado Look up -ado at Dictionary.com
in commando, desperado, tornado, and other words of Spanish and Portuguese origin, "person or group participating in an action," from Latin -atus, past participle suffix of verbs of the first conjugation (see -ade).
-ae Look up -ae at Dictionary.com
occasional plural suffix of words ending in -a, most of which, in English, are from Latin nominative fem. singular nouns, which in Latin form their plurals in -ae. But plurals in -s were established early in English for many of them (such as idea, arena) and many have crossed over since. Now it is not possible to insist on purity one way or the other without breeding monsters.
-age Look up -age at Dictionary.com
word-forming element in nouns of act, process, function, condition, from Old French and French -age, from Late Latin -aticum "belonging to, related to," originally neuter adjectival suffix, from Latin -atus, pp. suffix of verbs of the first conjugation.
-aholic Look up -aholic at Dictionary.com
word-forming element abstracted from alcoholic; first in sugarholic (1965), foodoholic (sic., 1965); later in workaholic (1968), golfaholic (1971), chocoholic (1971), and shopaholic (1984).
-al (1) Look up -al at Dictionary.com
suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).
-al (2) Look up -al at Dictionary.com
suffix forming nouns of action from verbs, mostly from Latin and French, meaning "act of ______ing" (such as survival, referral), Middle English -aille, from French feminine singular -aille, from Latin -alia, neuter plural of adjective suffix -alis, also used in English as a noun suffix. Nativized in English and used with Germanic verbs (as in bestowal, betrothal).
-al (3) Look up -al at Dictionary.com
word-forming element in chemistry to indicate "presence of an aldehyde group" (from aldehyde). The suffix also is commonly used in forming the names of drugs, often narcotics (such as barbital), a tendency that apparently began in German and might have been suggested by chloral (n.).
-algia Look up -algia at Dictionary.com
word-forming element denoting "pain," from Greek algos "pain," algein "to feel pain," of unknown origin. Related to alegein "to care about," originally "to feel pain."
-amide Look up -amide at Dictionary.com
also amide, in chemical use, 1850, word-forming element denoting a compound obtained by replacing one hydrogen atom in ammonia with an element or radical, from French amide, from ammonia + -ide.
-an Look up -an at Dictionary.com
word-forming element meaning "pertaining to," from Latin -anus, in some cases via French -ain, -en.
-ana Look up -ana at Dictionary.com
or ana, word-forming element denoting "collection of sayings, gossip, etc. connected with a person or place," early 18c., originally the neuter plural ending of Latin adjectives ending in -anus "pertaining to," from PIE adjectival suffix *-no-.
-ance Look up -ance at Dictionary.com
word-forming element attached to verbs to form abstract nouns of process or fact (convergence from converge), or of state or quality (absence from absent); ultimately from Latin -antia and -entia, which depended on the vowel in the stem word.

As Old French evolved from Latin, these were leveled to -ance, but later French borrowings from Latin (some of them subsequently passed to English) used the appropriate Latin form of the ending, as did words borrowed by English directly from Latin (diligence, absence).

English thus inherited a confused mass of words from French and further confused it since c.1500 by restoring -ence selectively in some forms of these words to conform with Latin. Thus dependant, but independence, etc.
-ancy Look up -ancy at Dictionary.com
word-forming element denoting quality or state, from Latin -antia, forming abstract nouns on pp. adjectives in -antem, appearing in English mostly in words borrowed directly from Latin (those passing through French usually have -ance or -ence; see -ance).
-ane Look up -ane at Dictionary.com
word-forming element in chemical use, indicating a chain of carbon atoms with no double bonds, proposed 1866 by German chemist August Wilhelm von Hofmann (1818-1892) to go with -ene, -ine (2), -one.
-ant Look up -ant at Dictionary.com
agent or instrumental suffix, from Old French and French -ant, from Latin -antem, accusative of -ans, present participle suffix of many Latin verbs.
-ar Look up -ar at Dictionary.com
word-formation element meaning "pertaining to, of the nature of," from Latin -arem, -aris "of the kind of, belonging to," a secondary form of -alis, dissimilated for used after syllables with an -l- (such as insularis for *insulalis, stellaris for *stellalis).
-arch Look up -arch at Dictionary.com
word-forming element meaning "a ruler," from Greek arkhos "leader, chief, ruler," from arkhe "beginning, origin, first place" (see archon).
-archy Look up -archy at Dictionary.com
word-forming element meaning "rule," from Latin -archia, from Greek -arkhia "rule," from arkhos "leader, chief, ruler," from arkhe "beginning, origin, first place" (see archon).
-ard Look up -ard at Dictionary.com
also -art, from Old French -ard, -art, from German -hard, -hart "hardy," forming the second element in many personal names, often used as an intensifier, but in Middle High German and Dutch used as a pejorative element in common nouns, and thus passing into Middle English in bastard, coward, blaffard ("one who stammers"), etc. It thus became a living element in English, as in buzzard, drunkard.
-ary Look up -ary at Dictionary.com
adjective and noun suffix, in most cases from Latin -arius, -aria, -arium "connected with, pertaining to; the man engaged in," from PIE relational adjective suffix *-yo- "of or belonging to." It appears in words borrowed from Latin in Middle English. In later borrowings from Latin to French, it became -aire and passed into Middle English as -arie, subsequently -ary.
-ase Look up -ase at Dictionary.com
word-forming element used in naming enzymes, from ending of diastase.
-ast Look up -ast at Dictionary.com
agential suffix, cognate with -ist, from French -ast, from Latin -asta, from Greek -astes.
-aster Look up -aster at Dictionary.com
word-forming element expressing incomplete resemblance (such as poetaster), usually diminutive and deprecatory, from Latin, from Greek -aster, suffix originally forming nouns from verbs ending in -azein, later generalized as a pejorative suffix, as in Greek patraster "he who plays the father."
-ate (1) Look up -ate at Dictionary.com
word-forming element used in forming nouns from Latin words ending in -atus, -atum (such as estate, primate, senate). Those that came to English via Old and Middle French often arrived with -at, but an -e was added after c.1400 to indicate the long vowel.

The suffix also can mark adjectives, formed from Latin past participals in -atus, -ata (such as desolate, moderate, separate), again, they often were adopted in Middle English as -at, with an -e appended after c.1400.
-ate (2) Look up -ate at Dictionary.com
verbal suffix for Latin verbs in -are, identical with -ate (1). Old English commonly made verbs from adjectives by adding a verbal ending to the word (such as gnornian "be sad, mourn," gnorn "sad, depressed"), but as the inflections wore off English words in late Old and early Middle English, there came to be no difference between the adjective and the verb in dry, empty, warm, etc. Thus accustomed to the identity of adjectival and verbal forms of a word, the English, when they began to expand their Latin-based vocabulary after c.1500, simply made verbs from Latin past-participial adjectives without changing their form (such as aggravate, substantiate) and it became the custom that Latin verbs were anglicized from their past participle stems.
-ate (3) Look up -ate at Dictionary.com
in chemistry, word-forming element used to form the names of salts from acids in -ic; from Latin -atus, -atum, suffix used in forming adjectives and thence nouns; identical with -ate (1).
The substance formed, for example, by the action of acetic acid (vinegar) on lead was described in the 18th century as plumbum acetatum, i.e. acetated lead. Acetatum was then taken as a noun meaning "the acetated (product)," i.e. acetate. [W.E. Flood, "The Origins of Chemical Names," London, 1963]
-athon Look up -athon at Dictionary.com
also -thon, word-forming element denoting prolonged activity and usually some measure of endurance, abstracted from marathon. E.g. walkathon (1931), skatathon (1933); talkathon (1948); telethon (1949).
-ation Look up -ation at Dictionary.com
word-forming element for making nouns of action; see -ion.
-ative Look up -ative at Dictionary.com
word-forming element meaning "of or related to; tending to," from Latin -ativus.
a (1) Look up a at Dictionary.com
indefinite article, mid-12c., a variation of Old English an (see an) in which the -n- began to disappear before consonants, a process mostly complete by mid-14c. The -n- also was retained before words beginning with a sounded -h- until c.1600; it still is retained by many writers before unaccented syllables in h- or (e)u-, but is now no longer normally spoken as such. The -n- also lingered (especially in southern England dialect) before -w- and -y- through 15c.
a (2) Look up a at Dictionary.com
as in twice a day, etc., from Old English an "on," in this case "on each." The sense was extended from time to measure, price, place, etc. The habit of tacking a onto a gerund (as in a-hunting we will go) died out 18c.
a capella Look up a capella at Dictionary.com
1876, earlier alla capella (1847), from Italian, "in the manner of the chapel," literally "according to the chapel," from cappella "chapel" (see chapel). Originally in reference to older church music (pre-1600) which was written for unaccompanied voices; applied 20c. to unaccompanied vocal music generally.
a deux Look up a deux at Dictionary.com
French, à deux, literally "for two" (see deuce).
a la Look up a la at Dictionary.com
from French à la, "in the manner of;" used in English in French terms from fashion or cookery since late 16c.; used in native formations with English words or names from c.1800 (first attested in Jane Austen).
a la carte Look up a la carte at Dictionary.com
1826, from French à la carte, literally "by the card" (see card (n.)); in other words, "ordered by separate items." Distinguished from a table d'hôte, meal served at a fixed, inclusive price.
a la mode Look up a la mode at Dictionary.com
1640s, from French à la mode (15c.), literally "in the fashion" (see mode (n.2)). In 17c., sometimes nativized as all-a-mode. Cookery sense of a dessert served with ice cream is 1903, American English.
a posteriori Look up a posteriori at Dictionary.com
Latin, literally "from what comes after" (see posterior).
a priori Look up a priori at Dictionary.com
1710, "from cause to effect" (a logical term, in reference to reasoning), Latin, literally "from what comes first," from priori, ablative of prior "first" (see prior (adj.)). Used loosely for "in accordance with previous knowledge" (1834).
A&P Look up A&P at Dictionary.com
U.S. grocery chain, originally The Great Atlantic and Pacific Tea Company, founded 1859 by George Huntington Hartford and George Gilman.
a- (1) Look up a- at Dictionary.com
in native (derived from Old English) words, it most commonly represents Old English an "on" (see a (2)), as in alive, asleep, abroad, afoot, etc., forming adjectives and adverbs from nouns; but it also can be Middle English of, as in anew, abreast (1590s); or a reduced form of Old English past participle prefix ge-, as in aware; or the Old English intensive a-, as in arise, awake, ashame, marking a verb as momentary, a single event. In words from Romanic languages, often it represents Latin ad- "to, at."
[I]t naturally happened that all these a- prefixes were at length confusedly lumped together in idea, and the resultant a- looked upon as vaguely intensive, rhetorical, euphonic, or even archaic, and wholly otiose. [OED]
a- (2) Look up a- at Dictionary.com
prefix meaning "not," from Latin a-, short for ab "away from" (as in avert), or its cognate, Greek a-, short for apo "away from, from," both cognate with Sanskrit apa "away from," Gothic af, Old English of (see apo-).
a- (3) Look up a- at Dictionary.com
prefix meaning "not," from Greek a-, an- "not," from PIE root *ne "not" (see un-).
A-1 Look up A-1 at Dictionary.com
in figurative sense of "first-rate," 1837, in Dickens; from Lloyd's of London designation for ships in first-class condition (with the letter referring to the condition of the ship and the number to that of the stores).