The Collaborative International Dictionary of English v.0.48:

Bub \Bub\, n.
   Strong malt liquor. [Cant] --Prior.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bub \Bub\, n. [Cf. 2d Bubby.]
   A young brother; a little boy; -- a familiar term of address
   of a small boy.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bub \Bub\, v. t. [Abbrev. from Bubble.]
   To throw out in bubbles; to bubble. [Obs.] --Sackville.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

63 Moby Thesaurus words for "bub":
   aunt, auntie, blood brother, boy, brethren, brother, bubba, buck,
   bud, buddy, colt, country cousin, cousin, cousin once removed,
   cousin twice removed, cub, daughter, father, fellow, first cousin,
   fledgling, foster brother, frater, grandnephew, grandniece,
   granduncle, great-aunt, great-uncle, half brother, hobbledehoy,
   kid brother, lad, laddie, manchild, master, mother, muchacho,
   nephew, niece, nuncle, nunks, nunky, pup, puppy, schoolboy,
   second cousin, sis, sissy, sister, sister-german, sistern, son,
   sonny, sonny boy, stepbrother, stepsister, unc, uncle, uncs,
   uterine brother, whelp, young man, youth