The Collaborative International Dictionary of English v.0.48:

pub \pub\ (p[u^]b), n. [Shortened from Public house.]
   A retail business where alcoholic beverages are sold by the
   drink; a bar; a tavern.
   [PJC]

WordNet (r) 3.0 (2006):

pub
    n 1: tavern consisting of a building with a bar and public
         rooms; often provides light meals [syn: public house,
         pub, saloon, pothouse, gin mill, taphouse]

Moby Thesaurus II by Grady Ward, 1.0:

51 Moby Thesaurus words for "pub":
   alehouse, bar, barrel house, barroom, beer garden, beer parlor,
   bistro, blind tiger, boardinghouse, cabaret, cafe, cocktail lounge,
   dive, dorm, dormitory, doss house, dramshop, drinkery,
   drinking saloon, fleabag, flophouse, gin mill, groggery, grogshop,
   guest house, honky-tonk, hospice, hostel, hostelry, hotel, inn,
   local, lodging house, nightclub, ordinary, pension, posada,
   pothouse, public, public house, rathskeller, roadhouse,
   rooming house, rummery, rumshop, saloon, saloon bar, speakeasy,
   taproom, tavern, wine shop



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

PUB
       Physical Unit Block


The Free On-line Dictionary of Computing (30 December 2018):

PUB

   1. PUBlishing.  A 1972 text-formatting language for TOPS-10,
   with syntax based on SAIL.  Influenced TeX and Scribe.
   ["PUB: The Document Compiler", Larry Tesler, Stanford AI Proj
   Op Note, Sept 1972].

   2. /pub, the top-level, publicly accessible directory on most
   anonymous FTP archives.  This is usually where the
   interesting files are.  See pubic directory.