/ Dictionary / Index C cogito, ergo sum*: Meaning and Definition of Find definitions for: co•gi•to er•go sum Pronunciation: (kō'gi-tō" er'gō soom' Eng. koj'i-tō" ûr'gō sum', er'gō), [key] — Latin. Latin. I think, therefore I am (stated by Descartes as the first principle in resolving universal doubt). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. cogitative cog locomotive Related Content Daily Word Quiz: pedagogy Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language