/ Dictionary / Index Q QCD: Meaning and Definition of Find definitions for: QCD Pronunciation: [key] — Physics. Physics. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: qcd (Thesaurus) Q.C. Q-Celtic Related Content Daily Word Quiz: beseech Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language