The Collaborative International Dictionary of English v.0.48:

Teak \Teak\ (t[=e]k), n. [Malayalam tekku.] (Bot.)
   A tree of East Indies (Tectona grandis) which furnishes an
   extremely strong and durable timber highly valued for
   shipbuilding and other purposes; also, the timber of the
   tree. [Written also teek.]
   [1913 Webster]

   African teak, a tree (Oldfieldia Africana) of Sierra
      Leone; also, its very heavy and durable wood; -- called
      also African oak.

   New Zeland teak, a large tree (Vitex littoralis) of New
      Zeland; also, its hard, durable timber.
      [1913 Webster]

WordNet (r) 3.0 (2006):

teak
    n 1: hard strong durable yellowish-brown wood of teak trees;
         resistant to insects and to warping; used for furniture and
         in shipbuilding [syn: teak, teakwood]
    2: tall East Indian timber tree now planted in western Africa
       and tropical America for its hard durable wood [syn: teak,
       Tectona grandis]