Entry 1 sense Webster, 1913 Inverisimilitude · In·ver·i·si·mil·i·tude · IPA /ɪnˌvɛɹɪsɪˈmɪlɪt(j)uːd/ 01 n. Lack of verisimilitude or likelihood; improbability. 1. Lack of verisimilitude or likelihood; improbability.