The Collaborative International Dictionary of English v.0.48:

Cognoscente \Cog`nos*cen"te\, n.; pl. Cognoscenti. [OIt.
   cognoscente, p. pr. of cognoscere, It. conoscere to know.]
   A connoisseur. --Mason.
   [1913 Webster]

WordNet (r) 3.0 (2006):

cognoscente
    n 1: an expert able to appreciate a field; especially in the
         fine arts [syn: connoisseur, cognoscente]

Moby Thesaurus II by Grady Ward, 1.0:

47 Moby Thesaurus words for "cognoscente":
   aesthete, amateur, annotator, arbiter, arbiter elegantiarum,
   arbiter of taste, authority, bon vivant, captious critic, carper,
   caviler, censor, censurer, collector, commentator, commenter,
   connaisseur, connoisseur, critic, criticaster, criticizer,
   critickin, criticule, dab, dilettante, editor, epicure, epicurean,
   expert, faultfinder, good judge, gourmand, gourmet, judge,
   literary critic, man of letters, maven, muckraker, proficient,
   refined palate, reviewer, scholiast, smellfungus, social critic,
   specialist, textual critic, virtuoso