Entry 1 sense Webster, 1913 Fitful /fĭt'-fəl/ · Fit·ful · IPA /ˈfɪtf(ə)l/ 01 a. Full of fits; irregularly variable; impulsive and unstable. 1. Full of fits; irregularly variable; impulsive and unstable. “After life's fitful fever, he sleeps well.” — Shak. “The victorious trumpet peal Dies fitfully away.” — Macaulay.