A person who is incompetent or mediocre at something, especially golf.
Origin uncertain, but possibly from Scottish 'doof' meaning 'stupid,' or related to peddlers ('duffers') who sold fake goods. It entered common usage in golf in the early 20th century.
The golf meaning became so dominant that 'duffer' is almost exclusively used in golf contexts—it's one of the few insults in the sport that's meant to be affectionate rather than cruel!
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