/ Dictionary / Index C couldst: Meaning and Definition of Find definitions for: couldst Pronunciation: (koodst, kootst), [key] — auxiliary v.andv. Archaic. 2nd pers. sing. pt. of Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. couldn't coulee 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