/ Dictionary / Index T trid.: Meaning and Definition of Find definitions for: trid. Pronunciation: [key] (in prescriptions) three days. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tricyclic Tridacna* Related Content Daily Word Quiz: soporific Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language