gumshoe

gumshoe

slang A detective or investigator. Don't worry, we'll find the thief—I have a gumshoe on the case now.

Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

gumshoe

(ˈgəmˈʃu)

n. a policeman or a detective. (Underworld. Also a term of address. So named for wearing silent, gum-rubber soles.) Has that gumshoe been around asking questions again?

McGraw-Hill's Dictionary of American Slang and Colloquial Expressions Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.