IMMATERIAL. What is not essential; unimportant what is not requisite; what is informal; as, an immaterial averment, an immaterial issue. 2. When a witness deposes to something immaterial, which is false, although he is guilty of perjury in foro conscientiae, he cannot be punished for perjury. 2 Russ. on Cr. 521; 1 Hawk. b. 1, c. 69, s. 8; Bac. Ab. Perjury, A.