fit up verb 3fit-up noun 2forms 4 verb3 •To furnish with suitable things; to prepare; to fit out.to fit up a room for a guestThe shoemaker will fit you up with a fine pair of boots. •To create a set or performance venue; to make a venue ready for a performance.We will finish fitting up the stage by the time the show starts. •(slang) Conspire to incriminate falsely a presumably innocent person.The gun was placed in her car in an effort to fit her up. fit-up noun2 •(slang) A stitch-up (act arranged to incriminate somebody). •A portable stage that can be disassembled and taken from one venue to another. formsfitted up · fitting up · fits up · fit-ups