/ Dictionary / Index R rationality: Meaning and Definition of Find definitions for: ra•tion•al•i•ty Pronunciation: (rash"u-nal'i-tē), [key] — pl. -ties. the state or quality of being rational. the possession of reason. agreeableness to reason; reasonableness. the exercise of reason. a reasonable view, practice, etc. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rationality (Thesaurus) rationalism rationalize Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language