tin foil hat

• tin-foil hat
• tinfoil hat

tin foil hat (plural tin foil hats)

1. 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.

   Synonym: (abbreviation) TFH

   • 1916, Roger W Allen (ed.), Millinery Trade Review, volume 41, page 27:

     Jeanne Due's ingenuity has sent the most remarkable of hats, this being the now notorious tinfoil hat, pictured elsewhere. The strangest part about this weird creation, however, is the fact that it is not unbecoming, but quite wearable.

   • 2001, Eoin Colfer, Artemis Fowl, page 42:

     To prevent them from reading his mind, he wore a tinfoil hat at all times.

   • 2008, Libby Sternberg, Recovering Dad, page 27:

     I mean, as much as any daughter, I want to make sure my mother is headed for happiness and not heartbreak, but Connie's taken it up a notch, to tinfoil-hat territory.

• tinfoil hatter
• tinfoilhattery