/ Dictionary / Index T thingness: Meaning and Definition of Find definitions for: thing•ness Pronunciation: (thing'nis), [key] — n. objective reality. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thing-in-itself thingstead Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language