tin hat

American  

noun

Slang.

1. a steel helmet worn by soldiers.

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tin hat British  

noun

1. obsolete a steel helmet worn by military personnel for protection against small metal fragments

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Etymology

Origin of tin hat

First recorded in 1915–20

Example Sentences

Diomande's act of foolishness just put the tin hat on it.

From BBC

One government source said to me: "It's definitely not tin hat time yet."

From BBC

It's time to put on the tin hats and ignore the noise.

From BBC

“He must have gone down to Mar-a-Lago with Trump wearing their tin hats, I mean — what a conspiracy theory,” McAuliffe said.

From Washington Post

Written in the present tense, in short bursts, the text appears like chopped-up radio transmissions, dispatched from someone squirrelly wearing a tin hat and raised binoculars.

From Seattle Times