/ Dictionary / Index M molecular knife: Meaning and Definition of Find definitions for: molec'ular knife' Pronunciation: [key] a segment of genetic material that inhibits the reproduction of the AIDS virus by breaking up specific areas of the virus's genes. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. molecularity molecular orbital Related Content Daily Word Quiz: leonine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language