The Collaborative International Dictionary of English v.0.48:

Jack \Jack\ (j[a^]k), n. [Pg. jaca, Malayalam, tsjaka.] (Bot.)
   A large tree, the Artocarpus integrifolia, common in the
   East Indies, closely allied to the breadfruit, from which it
   differs in having its leaves entire. The fruit is of great
   size, weighing from thirty to forty pounds, and through its
   soft fibrous matter are scattered the seeds, which are
   roasted and eaten. The wood is of a yellow color, fine grain,
   and rather heavy, and is much used in cabinetwork. It is also
   used for dyeing a brilliant yellow. [Written also jak.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Jackwood \Jack"wood`\, n.
   Wood of the jack (Artocarpus integrifolia), used in
   cabinetwork.
   [1913 Webster]