tinfoil
Americannoun
noun
-
thin foil made of tin or an alloy of tin and lead
-
thin foil made of aluminium; used for wrapping foodstuffs
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
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
He was a 25-year-old tinkering with self-tanners, but all the intrigue and action seemed to be around the lab next door, with its strange music, flashing lights and tinfoil covering the porthole.
From The Wall Street Journal ● Mar. 18, 2026
It requires little effort to arrange the group’s most unhinged statements into a cornucopia of lunacy, surpassed in recent memory only by the tinfoil conspiracism of QAnon.
From Salon ● Jan. 20, 2026
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 ● Dec. 12, 2024
So I went to my hair cutter and had him do it, with the tinfoil and everything.
From Los Angeles Times ● May 28, 2024
She had made a cross by tying two grapevines together and covering them with tinfoil.
From "Summer of the Monkeys" by Wilson Rawls
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
