Source : Webster's Revised Unabridged Dictionary (1913)

Bub \Bub\, n.
   Strong malt liquor. [Cant] --Prior.

Bub \Bub\, n. [Cf. 2d {Bubby}.]
   A young brother; a little boy; -- a familiar term of address
   of a small boy.

Bub \Bub\, v. t. [Abbrev. from {Bubble}.]
   To throw out in bubbles; to bubble. [Obs.] --Sackville.