/ Dictionary / Index U underreact: Meaning and Definition of Find definitions for: un•der•re•act Pronunciation: (un"dur-rē-akt'), [key] — v.i. to react with less than the expected or appropriate emotion. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. underrate underreport 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