The Collaborative International Dictionary of English v.0.48:

Sandalwood \San"dal*wood\, n. [F. sandal, santal, fr. Ar.
   [,c]andal, or Gr. sa`ntalon; both ultimately fr. Skr.
   candana. Cf. Sanders.] (Bot.)
   (a) The highly perfumed yellowish heartwood of an East Indian
       and Polynesian tree (Santalum album), and of several
       other trees of the same genus, as the Hawaiian Santalum
       Freycinetianum and Santalum pyrularium, the Australian
       Santalum latifolium, etc. The name is extended to
       several other kinds of fragrant wood.
   (b) Any tree of the genus Santalum, or a tree which yields
       sandalwood.
   (c) The red wood of a kind of buckthorn, used in Russia for
       dyeing leather (Rhamnus Dahuricus).
       [1913 Webster]

   False sandalwood, the fragrant wood of several trees not of
      the genus Santalum, as Ximenia Americana, Myoporum
      tenuifolium of Tahiti.

   Red sandalwood, a heavy, dark red dyewood, being the
      heartwood of two leguminous trees of India (Pterocarpus
      santalinus, and Adenanthera pavonina); -- called also
      red sanderswood, sanders or saunders, and
      rubywood.
      [1913 Webster] Sandarach

The Collaborative International Dictionary of English v.0.48:

Redwood \Red"wood`\ (-w[oo^]d`), n. (Bot.)
   (a) A gigantic coniferous tree (Sequoia sempervirens) of
       California, and its light and durable reddish timber. See
       Sequoia.
   (b) An East Indian dyewood, obtained from Pterocarpus
       santalinus, Caesalpinia Sappan, and several other
       trees.
       [1913 Webster]

   Note: The redwood of Andaman is Pterocarpus dalbergioides;
         that of some parts of tropical America, several species
         of Erythoxylum; that of Brazil, the species of
         Humirium.
         [1913 Webster]

WordNet (r) 3.0 (2006):

Pterocarpus santalinus
    n 1: tree of India and East Indies yielding a hard fragrant
         timber prized for cabinetwork and dark red heartwood used
         as a dyewood [syn: red sandalwood, red sanders, red
         sanderswood, red saunders, Pterocarpus santalinus]