subatomic particle suffix, from ion.

word-forming element meaning "having a center (of a certain kind); centered on," from Latinized form of Greek kentrikos "pertaining to a center," from kentron (see center (n.)).

word-forming element meaning "toward or on the right-hand side," from combining form of Latin dexter (from PIE root *deks- "right, opposite of left; south").

spelling conventional in 15c.-17c. English to add emphasis to borrowed French nouns ending in stressed -on; also used to represent Italian -one, Spanish -ón; all from Latin -onem. Compare shalloon (1670s) for French chalon, a kind of material used for linings. The ending is used occasionally to form words in English, such as spittoon, quadroon, and some older ones no longer with us, such as shabberoon "disreputable person" (c. 1700).

word-forming element meaning "eating, feeding on," from Latin -phagus, from Greek -phagos "eater of," from phagein "to eat," literally "to have a share of food," from PIE root *bhag- "to share out, apportion; to get a share."

alternative form of plani- "flat, level" (based on Latin planus), but an identical word-forming element is used in sciences as a combining form of Greek planos "wandering" (see planet).

extended form of -ry sometimes used in forming modern abstract nouns, often for humorous effect, based on the many -try words where the -t- is part of the Latin stem (geometry, idolatry, industry, pedantry, etc.).

word-forming element, from Greek -oma, with -o-, lengthened stem vowel + -ma, suffix forming neuter nouns and nouns that indicate result of verbal action (equivalent of Latin -men); especially taken in medical use as "morbid growth, tumor," based on sarcoma, carcinoma.

suffix used to form the present participles of verbs and the adjectives derived from them, from Old English present-participle suffix -ende, from PIE *-nt- (cognates: German -end, Gothic -and, Sanskrit -ant, Greek -on, Latin -ans, -ens). The vowel weakened in late Old English and the spelling with -g began 13c.-14c. among Anglo-Norman scribes who naturally confused it with -ing (1).

compound adjectival word-forming element, usually interchangeable with -ic but sometimes with specialized sense (such as historic/historical, politic/political), Middle English, from Late Latin -icalis, from Latin -icus + -alis (see -al (1)). Probably it was needed because the forms in -ic often took on a noun sense (for example physic). Forms in -ical tend to be attested earlier in English than their twins in -ic.