APA Dictionary of Psychology

n. in linguistics, a modification in the form of a word, often by the addition of a suffix, that signals a change in tense, person, number, or case. Common inflections in English are the addition of -ed or -ing to signal the past tense or present participle of a verb and the addition of -s or -’s to signal the plural or possessive form of a noun. See morphology. —inflectional adj.