large beer mug
Refers to a large mug, typically used for serving draft beer. The prefix 大 indicates the large size.
See also: ジョッキ
居酒屋で大ジョッキを注文した。
I ordered a large beer mug at the izakaya.
Compound of 大 (large) and ジョッキ (beer mug, from English 'jug').