Entry 1 sense Webster, 1913 Harum-scarum /(hâr"ŭm*skâr"ŭm)/ · Har·um-scar·um · IPA /ˌhɛəɹəmˈskɛəɹəm/ 01 a. Wild; giddy; flighty; rash; thoughtless. 1. Wild; giddy; flighty; rash; thoughtless.[Colloq.] “They had a quarrel with Sir Thomas Newcome's own son, a harum-scarum lad.” — Thackeray.