A silly, clumsy, or foolish person who does goofy things and makes people laugh.
From 'goof' (1920s slang, possibly from Yiddish 'gofen') combined with 'ball.' The term became popular in mid-20th century American English to describe a lovably silly person.
Goofball entered youth culture through cartoons and TV, becoming a term of affection rather than pure insult—it describes someone whose silliness is endearing rather than malicious, which says something about how English categorizes different types of foolishness.
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