Entry 1 sense Webster, 1913 Let-up /(lĕt"ŭp`)/ · Let·-up · IPA /lˈɛtˌʌp/ 01 n. Abatement; also, cessation; as, it blew a gale for three days without any let-up. 1. Abatement; also, cessation; as, it blew a gale for three days without any let-up.[Colloq.]