/ Dictionary / Index I in-service: Meaning and Definition of Find definitions for: in-serv•ice Pronunciation: (in-sûr'vis, in'sûr"-), [key] — adj. taking place while one is employed: an in-service training program. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. insertion insessorial Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language