v. i. To drink largely or luxuriously. [ 1913 Webster ]

Twelve days the gods their solemn revels keep,
And quaff with blameless Ethiops in the deep. Dryden. [ 1913 Webster ]

v. t. [ imp. & p. p. Quaffed p. pr. & vb. n. Quaffing. ] [ For quach, fr. Gael. & Ir. cuach a drinking cup; cf. L. caucus a drinking vessel. Cf. Quaigh. ] To drink with relish; to drink copiously of; to swallow in large draughts. “Quaffed off the muscadel.” Shak. [ 1913 Webster ]

They eat, they drink, and in communion sweet
Quaff immortality and joy. Milton. [ 1913 Webster ]

n. One who quaffs, or drinks largely. [ 1913 Webster ]