Burn

Burn' refers to the permanent removal of a cryptoasset from circulation, typically accomplished by transferring the asset to a wallet address ('burn address') unable to be accessed by any user.

Token burns are often paired with buybacks to reduce circulating supply. Since burned tokens are unrecoverable and, thus, unable to be reintroduced to circulating supply, any cryptoeconomic mechanism resulting in a burn is a type of hard sink.