Entry 1 sense Webster, 1913 Wonderful /wŭn'-dẽrf-əl/ · Won·der·ful · IPA /ˈwʌn.dɚ.fl̩/ 01 a. Adapted to excite wonder or admiration; surprising; strange; astonishing. 1. Adapted to excite wonder or admiration; surprising; strange; astonishing. Syn. Marvelous; amazing. See Marvelous.