Wiktionary
alt. A piece of headgear made from one or more sheets of tin foil, aluminium foil, or other similar material, especially when worn in the belief that it shields the brain from electromagnetic fields, or against mind control and/or mind reading. n. A piece of headgear made from one or more sheets of tin foil, aluminium foil, or other similar material, especially when worn in the belief that it shields the brain from electromagnetic fields, or against mind control and/or mind reading.
Usage examples of "tinfoil hat".
One could have a more fruitful discussion with a paranoid schizophrenic about his tinfoil hat than with liberals about Soviet spies crawling through Democratic administrations at the onset of the Cold War.
Leonardo da Vinci, which we can prove by citing his most famous self-portrait, in which he depicted himself wearing a pyramid-shaped tinfoil hat.
To prevent them reading his mind, he wore a tinfoil hat at all times.