Armed support? Chuck it! (5)

I believe the answer is:

sling

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'armed support? chuck' is the definition.
'sling' can be an answer for 'chuck' (chuck means throw as does sling). I am unsure of the 'armed support?' bit.

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for sling that I've seen before include "Keeping afloat" , "American drink" , "throwing implement like catapult" , "Support bandage; drink" , "Move off!" .)

I've seen this clue in the Evening Standard.

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