Mandatory method? (5)
I believe the answer is:
order
This might be a double definition.
'mandatory' is the first definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'method?' is the second definition.
(thesaurus)
Can you help me to learn more?
(Other definitions for order that I've seen before include "Type of column" , "the Speaker often calls for" , "Command; arrange" , "association" , "Command or request for goods" .)