Plural of gumshoe; detectives, private investigators, or secret agents; also literal rubber-soled shoes.
From 'gum' (rubber) plus 'shoes' (footwear). Originally referred to the quiet rubber-soled shoes detectives wore, then became slang for the detectives themselves.
Gumshoes are one of slang's greatest linguistic gifts—take an article of clothing (rubber shoes) and suddenly you've got a one-word description of an entire profession that lasted for decades in common speech!
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