- tinfoil⇄adj. of, made of, or wrapped in tinfoil.
- tinfoil⇄noun Also, tin foil.1. a very thin sheet of tin, or of an alloy of tin and lead, used as a wrapping for candy, tobacco, or similar articles.
2. tin hammered or rolled into a thin sheet and coated with mercury, used for backing mirrors and other p - tinfoil⇄tinfoil, noun, adjective.