/ Dictionary / Index H humidistat: Meaning and Definition of Find definitions for: hu•mid•i•stat Pronunciation: (hy-mid'u-stat" or, often, y-), [key] — n. an instrument for measuring and controlling humidity. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. humidify humidity Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language