/ Dictionary / Index R regular tertiaries: Meaning and Definition of Find definitions for: reg'ular ter'tiaries. Pronunciation: [key] See under(def. 5). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. regular ode regular year Related Content Daily Word Quiz: philtrum Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language