/ Dictionary / Index T thermoperiodic: Meaning and Definition of Find definitions for: ther•mo•pe•ri•od•ic Pronunciation: (thûr"mō-pēr"ē-od'ik), [key] — adj. Biol. responding to or affected by periodic differences in temperatures. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Thermopane thermoperiodicity Related Content Daily Word Quiz: jugular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language