/ Dictionary / Index D derived unit: Meaning and Definition of Find definitions for: derived' u'nit Pronunciation: [key] (in physics, chemistry, etc.) a unit derived from fundamental units of length, mass, and time. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. derived form Derleth Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language