I have seen the word "temp" used in many attributions. What does it mean? Any insight would be helpful.
I may be wrong, but I think it means "in the time of" or "around the time of", from Latin tempore. Edited to add that I googled it and this is correct It's not just seen in Mongol coins. You'll find it in many attributions in which the precise timeframe isn't known. Examples from CNG's archives: KINGS of LYDIA. temp. Ardys – Alyattes. Circa 630s-564/53 BC PERSIA, Achaemenid Empire. temp. Darios I to Xerxes II. Circa 485-420 BC
Many of the coins from the early Mongol supremacy era could better be considered as semi-autonomous city issues. On the coins that do refer to a ruler, many do not specify a name but just give a title as "Khaqan al-adil" (the great Khan). I also have the impression that some sellers try to make some obscure coins more appealing by stating an attribution like "temp. Chingiz Khan".