Definition of draught noun from the Oxford Advanced Learner's Dictionary

draught

noun
drɑːft
 
; drɑːft
 
(British English) (North American English draft)
 
1 [countable] a flow of cool air in a room or other confined spaceThere's a draught in here.A cold draught of air blew in from the open window.I was sitting in a draught.She shivered in the icy draught.2 [countable] (formal) one continuous action of swallowing liquid; the amount swallowedHe took a deep draught of his beer.3 [countable] (old use or literary) medicine in a liquid forma sleeping draught (= one that makes you sleep)4 draughts (British English) (North American English checkers) [uncountable] a game for two players using 24 round pieces on a board marked with black and white squares5 [countable] (British English) (North American English checker) one of the round pieces used in a game of draughts
Idioms

on draught

(British English) (of beer) taken from a large container (= a barrel )This beer is not available on draught (= it is available only in bottles or cans).