| a suffix, appearing in words of Latin origin, denoting action or condition, used in Latin and in English to form nouns from stems of Latin adjectives (communion; union), verbs (legion; opinion), and esp. past participles (allusion; creation; fusion; notion; torsion). |
| a suffix occurring in words of Latin origin, used to form abstract nouns from verbs or stems not identical with verbs, whether as expressing action (revolution; commendation), or a state (contrition; starvation), or associated meanings (relation; temptation). |
| -ation suff.
[Middle English -acioun, from Old French -ation, from Latin -ātiō, -ātiōn-, n. suff. : -ā-, stem vowel of verbs in -āre + -tiō, -tiōn-, abstract n. suff.] |