agential suffix, from French -ast, from Latin -asta, from Greek -astes, the form of -istes (see -ist) used after -i-.
word-formation element meaning "pertaining to, of the nature of," from Latin -arem, -aris "of the kind of, belonging to," a secondary form (by dissimilation) of -alis, used after syllables with an -l- (such as insularis for *insulalis, stellaris for *stellalis).
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 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 participles 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.
"factitious slang suffix" (OED), sometimes affectionate, forming nouns indicating "a humorous or remarkable instance" of what is indicated, in use by 1940s (e.g. smasheroo "spectacular success," by 1948), perhaps from buckaroo. An earlier suffix in a similar sense is -erino (after 1900), apparently from -er + Italian suffix -ino.
word-forming element used in World War II armed forces slang and after, meaning "crazed or frazzled from stress due to" the thing specified (as in bomb-happy (1942), flak-happy (1943), trigger-happy (1942). The model might have been slap-happy in pugilism from 1936 as a slang variant of "punch-drunk."
word-forming element making adjectives from nouns or verbs, from French -ent and directly from Latin -entem (nominative -ens), present-participle ending of verbs in -ere/-ire. Old French changed it in many words to -ant, but after c. 1500 some of these in English were changed back to what was supposed to be correct Latin. See -ant.
instrumental word-forming element, expressing "appliance, tool," from Old English -ol, -ul, -el, representing PIE *-lo- (see -ule). In modern English usually -le except after -n-. As in treadle, ladle, thimble, handle, spindle, girdle; also compare dialectal thrashle "flail, implement for thrashing," from Old English ðerscel, Middle English scrapel "instrument for scraping" (mid-14c.), etc.
suffix forming nouns of action, state, or quality from verbs or adjectives (such as depth, strength, truth), from Old English -ðu, -ð, from Proto-Germanic *-itho (cognates: Old Norse -þ, Old High German -ida, Gothic -iþa), abstract noun suffix, from PIE *-ita (cognates: Sanskrit -tati-; Greek -tet-; Latin -tati-, as in libertatem "liberty" from liber "free"). Sometimes in English reduced to -t, especially after -h- (as in height).