Source : Webster's Revised Unabridged Dictionary (1913)

Simoom \Si*moom"\, Simoon \Si*moon"\, n. [Ar. sam?m, fr. samma
   to poison. Cf. {Samiel}.]
   A hot, dry, suffocating, dust-laden wind, that blows
   occasionally in Arabia, Syria, and neighboring countries,
   generated by the extreme heat of the parched deserts or sandy
   plains.

Source : WordNet®

simoon
     n : a violent hot sand-laden wind on the deserts of Arabia and
         North Africa [syn: {simoom}, {samiel}]