adj. Of, relating to, or of the nature of an illation.adj. Expressing or preceding an inference. Used of a word.adj. Grammar Of, relating to, or being a grammatical case indicating motion toward or into in some languages, as in Finnish Helsinkiin, "to Helsinki.”n. A word or phrase, such as hence or for that reason, that expresses an inference.n. See illation.n. Grammar The illative case.n. Grammar A word or form in the illative case.