Someone who repairs broken things or solves problems, or someone who handles problems through questionable means.
From 'fix' (possibly from Latin 'fixus' meaning fastened) plus agent suffix '-er'; the shady meaning developed in political slang by the early 1900s.
A 'fixer' in movies and politics is someone who 'fixes' problems by making them disappear—the same word covers both the plumber and the crime syndicate member!
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