The Collaborative International Dictionary of English v.0.48:

Waldenses \Wal*den"ses\ (?; 277), n. pl. [So called from Petrus
   Waldus, or Peter Waldo, a merchant of Lyons, who founded this
   sect about a. d. 1170.] (Eccl. Hist.)
   A sect of dissenters from the ecclesiastical system of the
   Roman Catholic Church, who in the 13th century were driven by
   persecution to the valleys of Piedmont, where the sect
   survives. They profess substantially Protestant principles.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Waldenses
    n 1: a Christian sect of dissenters that originated in southern
         France in the late 12th century adopted Calvinist doctrines
         in the 16th century [syn: Waldenses, Vaudois]