Source : Webster's Revised Unabridged Dictionary (1913)

Sirocco \Si*roc"co\ (s[i^]*r[o^]k"k[-o]), n.
   In general, any hot dry wind of cyclonic origin, blowing from
   arid or heated regions, including the desert wind of Southern
   California, the harmattan of the west coasts of Africa, the
   hot winds of Kansas and Texas, the kamsin of Egypt, the leste
   of the Madeira Islands, and the leveche of Spain.

Sirocco \Si*roc"co\, n.; pl. {Siroccos}. [It. sirocco, scirocco,
   Ar. shorug, fr. sharq the rising of the sun, the east, fr,
   sharaca to rise as the sun. Cf. {Saracen}.]
   An oppressive, relaxing wind from the Libyan deserts, chiefly
   experienced in Italy, Malta, and Sicily.

Source : WordNet®

sirocco
     n : a windstorm that lifts up clouds of dust or sand; "it was
         the kind of duster not experienced in years" [syn: {dust
         storm}, {duster}, {sandstorm}]