Entry 1 sense Webster, 1913 Hilarity /hĭl-ĕr'-ət-ē/ · Hi·lar·i·ty · IPA /hɪˈlæɹɪ.ti/ 01 n. Boisterous mirth; merriment; jollity. 1. Boisterous mirth; merriment; jollity. Syn. Glee; cheerfulness; mirth; merriment; gayety; joyousness; exhilaration; joviality; jollity.