/ Dictionary / Index I in vitro fertilization: Meaning and Definition of Find definitions for: in vi'tro fertiliza'tion Pronunciation: [key] a specialized technique by which an ovum, esp. a human one, is fertilized by sperm outside the body, with the resulting embryo later implanted in the uterus for gestation. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. in vitro in vivo 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