Source : Webster's Revised Unabridged Dictionary (1913)

Lightwood \Light"wood`\ (-w[oo^]d`), n.
   Pine wood abounding in pitch, used for torches in the
   Southern United States; pine knots, dry sticks, and the like,
   for kindling a fire quickly or making a blaze.

Source : WordNet®

lightwood
     n : tall Australian acacia yielding highly valued black timber
         [syn: {Acacia melanoxylon}]