/ Dictionary / Index R rad-lib: Meaning and Definition of Find definitions for: rad-lib Pronunciation: (rad'lib'), [key] — Informal. Informal. —n. a liberal, esp. a liberal politician, considered to have radical or extremist tendencies. —adj. being or of such a liberal; liberal tending toward radical: The congressman accused his opponent of holding rad-lib ideas. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. radix RAdm Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language