The Collaborative International Dictionary of English v.0.48:

Shittah \Shit"tah\, Shittah tree \Shit"tah tree`\, n. [Heb.
   shitt[=a]h, pl. shitt[imac]m.]
   A tree that furnished the precious wood of which the ark,
   tables, altars, boards, etc., of the Jewish tabernacle were
   made; -- now believed to have been the wood of the Acacia
   Seyal, which is hard, fine grained, and yellowish brown in
   color.
   [1913 Webster] Shittim