Thomas over at Jihadica
has a lot more on the term ruwaybidha,
including one of the traditions from which some version of the term stems,
also politely correcting my original transliteration. I still think that the term implies a sense of authority or responsibility, almost like a shepherd (al-rabidha
), coming from rabidh
(herd of sheep or goats). Al-Ruwaybidha
, then would be the diminutive of al-rabidha
and, of course, an insult.