Obligatory (10)
'obligatory' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for compulsory that I've seen before include "Mandatory" , "Obliged to be done" , "De rigueur" .)
'obligatory' is the definition.
(similar in meaning)
This is the entire clue.
(Other definitions for mandatory that I've seen before include "required" , "Not optional" , "Binding" , "Compulsory" , "Obligatory" .)