The object of which is to make a line of five men explode (6)
I believe the answer is:
gobang
'the object of which is to make a line of five men explode' is the definition.
The definition suggests a singular noun which matches the answer.
'the object of which is to make a' is the wordplay.
I cannot really understand how this works, but
'object' could be 'ob' (Ob is an example) and 'ob' is located in the answer.
'a' could be 'an' and 'an' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for gobang that I've seen is " Board game".)