Definition of "goofball"

goofball

/ˈɡufˌbɔl/

noun
plural goofballs
1. (informal, often derogatory, sometimes endearing) A foolish or silly person or animal.
2. (informal, pharmacology) A pill or tablet containing a pharmaceutical which has hypnotic or intoxicating effects, especially a barbiturate.
  Quotations
  Strong Cobb & Co. of Cleveland announced a new barbiturate which in overlarge doses will turn the stomachs of "goofball" addicts and would-be suicides.
  1953 April 27, “Capsules”, in Time
  That night Marylou took everything in the books; she took tea, goofballs, benny, liquor, and even asked Old Bull for a shot of M, which of course he didn’t give her; he did give her a martini.
  1957, Jack Kerouac, On the Road, Viking Press
adjective
not comparable
1. (informal) Silly.