Crossword Genius

Pins an opponent's arms making him defenceless? (6,3,4)

Ross

I believe the answer is:

spikes his guns

I'm a little stuck... Click here to teach me more about this clue!

'pins an opponent's' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'arms making him defenceless?' is the wordplay.
I cannot quite understand how this works, but
'arms' could be 'pikes' (pike is a kind of arm) and 'pikes' is found within the answer.
'him' could be 'gun' and 'gun' is located in the answer.
This may be the basis of clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in The Globe and Mail.
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