Iranian in origin, but the details are not understood; it is pre-Islamic, probably from Aramaic סַרְבְּלָא (sarbəlā), סַרְבַּלָא (sarbalā, “mantle; trousers”) or Aramaic סַרְבֵּל (sarbel, “to cloth with a mantle; to clothe with trousers”), and it is possible that the verbs came before the noun in Arabic and the noun is deverbal. Regard Persian شلوار (šalvâr, “trousers”).