/ Dictionary / Index I isotherm: Meaning and Definition of Find definitions for: i•so•therm Pronunciation: (ī'su-thûrm"), [key] — n. a line on a weather map or chart connecting points having equal temperature. Also calleda curve on which every point represents the same temperature. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: isotherm (Thesaurus) isothere isothermal Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language