fathead Meaning, Definition & Usage

  1. noun a man who is a stupid incompetent fool
    goof; cuckoo; goose; bozo; zany; twat; jackass; goofball.

WordNet

Fat"head` noun
Definitions
  1. (Zoöl.) (a) A cyprinoid fish of the Mississippi valley (Pimephales promelas); -- called also black-headed minnow. (b) A labroid food fish of California; the redfish.

Webster 1913