“The core concept of a bribe is an inducement improperly influencing the performance of a public function meant to be gratuitously exercised.” John T. Noonan Jr., Bribes xi (1984).
bribe
bribe, n. A price, reward, gift, or favor bestowed or promised with a view to pervert the judgment of or influence the action of a person in a position of trust. Cf. BARRATRY(4).