The Collaborative International Dictionary of English v.0.48:

speakeasy \speak"eas`y\, (sp[=e]k"[=e]`z[-e]) n.
   An establishment where alcoholic beverages were sold and
   drunk illegally, especially one operating during the
   prohibition era in the U.S. (1920-1932); a tavern or
   nightclub illegally selling alcoholic beverages.
   [PJC]

WordNet (r) 3.0 (2006):

speakeasy
    n 1: (during prohibition) an illegal barroom

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "speakeasy":
   alehouse, bar, barrel house, barroom, beer garden, beer parlor,
   bistro, blind tiger, cabaret, cafe, cocktail lounge, dive,
   dramshop, drinking saloon, gin mill, groggery, grogshop,
   honky-tonk, local, nightclub, pothouse, pub, public, public house,
   rathskeller, rumshop, saloon, saloon bar, taproom, tavern,
   wine shop



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

Speakeasy

   Simple array-oriented language with numerical integration and
   differentiation, graphical output, aimed at statistical
   analysis.

   ["Speakeasy", S. Cohen, SIGPLAN Notices 9(4), (Apr 1974)].

   ["Speakeasy-3 Reference Manual", S. Cohen et al. 1976].