(slang) strength or vitality; courage. They have a lot of nerve; they have a lot of guts. -Levels of Skill (6 July 1957)(colloquial) the basic, inner or deeper parts.(slang) daring, courage, etc.(slang) strength or vitality; courage.(slang) daring, courage, etc. It takes a little doing and it takes a little guts. iMarriage (2 Jan. 60)(slang) daring, courage, etc. It takes a little doing and it takes a little guts. ?Marriage (2 Jan. 60)