·noun Strong malt liquor.
II. Bub ·vt To throw out in bubbles; to Bubble.
III. Bub ·noun A young brother; a little boy;
— a familiar term of address of a small boy.
Strong beer. ...
Dictionary of The Vulgar Tongue by Francis Grose
A liquor or drink. Bub and grub meaning inversely meat and drink. ...
The Sailor's Word-Book