means a tall, one-handled drinking vessel, usually metal or pottery and sometimes fitted with a hinged lid, made for serving beer or other drink.

from English from at least the medieval period, but the deeper trail is murky. The popular guess links it to the same family as 'tank' (a large container), and there may be a connection to Middle Dutch 'tanckaert' — yet etymologists admit the word's origin is genuinely uncertain. An early sense even pointed to a big tub or open vessel, only later narrowing to the lidded ale-mug we picture today.