Actual leader of Moroccan kingdom (5)
I believe the answer is:
realm
'kingdom' is the definition.
(thesaurus)
'actual leader of moroccan' is the wordplay.
'actual' becomes 'real' ('real' can be a synonym of 'actual').
'leader of' indicates taking the first letters.
The initial letter of 'moroccan' is 'm'.
'real'+'m'='REALM'
(Other definitions for realm that I've seen before include "Kingdom; field of interest" , "Area of interest/activity" , "field of study" , "Lamer (anag.)" , "where ruler holds sway?" .)