The Collaborative International Dictionary of English v.0.48:

Santalum \San"ta*lum\, n. [NL. See Sandalwood.] (Bot.)
   A genus of trees with entire opposite leaves and small
   apetalous flowers. There are less than a dozen species,
   occurring from India to Australia and the Pacific Islands.
   See Sandalwood.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Santalum
    n 1: parasitic trees of Indonesia and Malaysia [syn: Santalum,
         genus Santalum]