Arab said to be upset about leader of ulema (5)
I believe the answer is:
saudi
'arab' is the definition.
(Saudi is an example)
'said to be upset about leader of ulema' is the wordplay.
'to be upset' indicates anagramming the letters.
'about' means one lot of letters goes inside another.
'leader of' says to take the initial letters.
The initial letter of 'ulema' is 'u'.
'said' is an anagram of 'sadi'.
'sadi' placed around 'u' is 'SAUDI'.
(Other definitions for saudi that I've seen before include "Native of Riyadh, perhaps" , "one accustomed to hot, dry conditions?" , "One from Riyadh" , "Arab" , "Middle-Easterner" .)