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]