The Collaborative International Dictionary of English v.0.48:

Savant \Sa`vant"\, n.; pl. Savants (F. ?; E. ?). [F., fr.
   savoir to know, L. sapere. See Sage, a.]
   A man of learning; one versed in literature or science; a
   person eminent for acquirements.
   [1913 Webster]

WordNet (r) 3.0 (2006):

savant
    n 1: someone who has been admitted to membership in a scholarly
         field [syn: initiate, learned person, pundit,
         savant]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "savant":
   Admirable Crichton, academician, adept, aficionado, amateur,
   artisan, artist, attache, authority, bookman, buff, classicist,
   clerk, colossus of knowledge, connaisseur, connoisseur, consultant,
   cordon bleu, crack shot, craftsman, critic, dead shot, dilettante,
   diplomat, diplomatist, doctor, elder, elder statesman,
   experienced hand, experimental scientist, expert,
   expert consultant, fan, freak, genius, giant of learning, graduate,
   great soul, guru, handy man, humanist, illuminate, intellect,
   intellectual, journeyman, learned clerk, learned man, literary man,
   litterateur, lover of learning, lover of wisdom, mahatma,
   man of intellect, man of learning, man of letters, man of science,
   man of wisdom, mandarin, marksman, master, mastermind, mentor,
   mine of information, no slouch, nut, oracle, philologist,
   philologue, philomath, philosophe, philosopher, politician,
   polyhistor, polymath, practical scientist, pro, professional,
   professor, proficient, pundit, rabbi, rishi, sage, sapient,
   scholar, scholastic, schoolman, scientist, seer, shark, sharp,
   specialist, starets, statesman, student, technical adviser,
   technical expert, technician, technologist, thinker,
   walking encyclopedia, wise man, wise old man