/ Dictionary / Index S subthreshold: Meaning and Definition of Find definitions for: sub•thresh•old Pronunciation: (sub-thresh'ōld, -thresh'hōld), [key] — adj. Psychol., Physiol. (of a stimulus) too weak to produce a response. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subtherapeutic subtile Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language