The Collaborative International Dictionary of English v.0.48:

Neishout \Neis"hout\, n. [From D. niezen to sneeze + hout wood.]
   (Bot.)
   The mahogany-like wood of the South African tree Pteroxylon
   utile, the sawdust of which causes violent sneezing (whence
   the name). Also called sneezewood.
   [1913 Webster]