/ Dictionary / Index T thermosiphon: Meaning and Definition of Find definitions for: ther•mo•si•phon Pronunciation: (thûr"mu-sī'fun), [key] — n. an arrangement of siphon tubes that enables water in a heating apparatus to circulate by means of convection. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. thermosetting thermosphere Related Content Daily Word Quiz: frugal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language