/ Dictionary / Index P placid: Meaning and Definition of Find definitions for: plac•id Pronunciation: (plas'id), [key] — adj. pleasantly calm or peaceful; unruffled; tranquil; serenely quiet or undisturbed: placid waters. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: placid (Thesaurus) placet Plácido's disk Related Content Daily Word Quiz: cur Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language