/ Dictionary / Index H hyperpituitarism: Meaning and Definition of Find definitions for: hy•per•pi•tu•i•ta•rism Pronunciation: (hī"pur-pi-t'i-tu-riz"um, -ty'-), [key] — n. Pathol. overactivity of the pituitary gland. a resultant condition, as giantism or acromegaly. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hyperpituitarism (Thesaurus) hyperphysical hyperplane Related Content Daily Word Quiz: profiterole Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language