Title of various Iranians (3)
I believe the answer is:
sir
'title' is the definition.
(respectful address for a man)
'of various iranians' is the wordplay.
'of' says the answer is hidden in the clue.
'SIR' can be found hidden inside 'various iranians'.
(Other definitions for sir that I've seen before include "Title given to 10 Across" , "Formal term of address" , "Term of address for a gentleman" , "Honorary male title" , "Polite form of address to a man" .)