/ Dictionary / Index T transmissivity: Meaning and Definition of Find definitions for: trans•mis•siv•i•ty Pronunciation: (trans"mi-siv'i-tē, tranz"-), [key] — n. Physics. a measure of the ability of a material or medium to transmit electromagnetic energy, as light. Cf. transmittance. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. trans-Mississippi transmissometer Related Content Daily Word Quiz: perspicacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language