/ Dictionary / Index I isogeotherm: Meaning and Definition of Find definitions for: i•so•ge•o•therm Pronunciation: (ī"su-jē'u-thûrm"), [key] — n. an imaginary line connecting all points within the earth having the same mean temperature. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. isogenous isogloss Related Content Daily Word Quiz: sequester Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language