D defs.my
Entry 1 sense Webster, 1913

doofus

· doo·fus · IPA /ˈduːfəs/
01 n. a person who is stupid or inept; -- used contemptuously.
  1. 1.
    a person who is stupid or inept; -- used contemptuously.[Slang]
Syn. dingdong, ding-a-ling.