/ Dictionary / Index L lactam: Meaning and Definition of Find definitions for: lac•tam Pronunciation: (lak'tam), [key] — n. Chem. any of a group of cyclic amides characterized by the NHCO group, derived from aminocarboxylic acids by the intramolecular elimination of water from the amino and carboxylic groups. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lactalbumin lactarian Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language