/ Dictionary / Index H hyperextension: Meaning and Definition of Find definitions for: hy•per•ex•ten•sion Pronunciation: (hī"pur-ik-sten'shun), [key] — n. the extension of a part of the body beyond normal limits. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hyperextension (Thesaurus) hyperexcitability hyperfine structure Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language