Entry 3 senses · 3 variants Webster, 1913 Fib /fĭb/ · IPA /fɪb/ n. v. i. v. t. 01 n. A falsehood; a lie; -- used euphemistically. 1. A falsehood; a lie; -- used euphemistically. “They are very serious; they don't tell fibs.” — H. James. 02 v. i. To speak falsely. imp. & p. p. Fibbed; p. pr. & vb. n. Fibbing 1. To speak falsely.[Colloq.] 03 v. t. To tell a fib to. 1. To tell a fib to.[R.]