tinfoil

American  

[tin-foil] / ˈtɪnˌfɔɪl /

noun

1. tin, or an alloy of tin and lead, in the form of a thin sheet, much used as a wrapping for drugs, foods, tobacco, etc.

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tinfoil British  

/ ˈtɪnˌfɔɪl /

noun

1. thin foil made of tin or an alloy of tin and lead

2. thin foil made of aluminium; used for wrapping foodstuffs

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Usage

What is a tinfoil hat? Tinfoil hat is a shorthand for saying someone believes in conspiracy theories, is paranoid, or is crazy more generally.

Etymology

Origin of tinfoil

First recorded in 1425–75, tinfoil is from the late Middle English word tynfoile. See tin, foil ²

Example Sentences

One suspect had an expensive phone wrapped in tinfoil in an attempt to block the device's signal and avoid it being traced.

From BBC

Every weekday morning, drivers arrive at the Little Tokyo Towers at 10 a.m. carrying precious cargo: seniors’ meals individually wrapped in tinfoil.

From Los Angeles Times

“I said, you know, I may sound like a crazy, tinfoil hat–wearing person,” Russo, also a veterinarian, recalled at a 5 April public talk sponsored by her company.

From Science Magazine

“I feel like if I raise those concerns, they want to put a tinfoil hat on me and they want to say I’m an anarchist or an insurrectionist,” Crye said.

From Seattle Times

As a familiar feral atmosphere gripped Rodney Parade and the tinfoil replica FA Cup trophies glistened under floodlit skies, it felt like another shock was brewing in Newport.

From BBC