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.
In 1905 Jacob Mohr, a German schizophrenic, believed that he was being targeted by an “oscillatory wave transmission device” and was found, on admission to hospital, to be wearing sheets of tinfoil under his clothes.
From The Wall Street Journal ● Oct. 16, 2026
During Monday’s hearing, he complained that mainstream news media, including the Washington Post, had portrayed him and his allies “like we have a tinfoil hat on our heads.”
From Slate ● Dec. 19, 2025
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 ● Oct. 4, 2024
A large roll of non-stick tinfoil couldn't hold a candle to Mamma Mia actress Amanda Seyfried, who wore a shiny metallic gown featuring flower appliques.
From BBC ● May 6, 2024
She brought empanadas and sugared breads wrapped in tinfoil, arroz con pollo and chicken soup packaged in plastic containers.
From "The Book of Unknown Americans" by Cristina Henríquez
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions 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.
