The Collaborative International Dictionary of English v.0.48:

Vandyke beard \Van*dyke" beard`\
   A trim, pointed beard, such as those often seen in pictures
   by Vandyke.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

vandyke beard
    n 1: a short pointed beard (named after the artist Anthony
         Vandyke) [syn: vandyke beard, vandyke]