Breadcrumb Home > Dictionary > Index T terraform: Meaning and Definition of Find definitions for: ter•ra•form Pronunciation: (ter'u-fôrm"), [key] — v.t. to alter the environment of (a celestial body) in order to make capable of supporting terrestrial life forms. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. terra firma terrain ✖ Related Content Daily Word Quiz: hegira Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language