A jolly woman in invasion force (6)

I believe the answer is:

armada

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'force' is the definition.
(I know that armada is a type of force)

'a jolly woman' is the wordplay.
'jolly' becomes 'RM' (jolly can mean a Royal Marine).
'woman' becomes 'Ada' (woman's name).
'a'+'rm'+'ada'='ARMADA'

'in invasion' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.

Can you help me to learn more?

(Other definitions for armada that I've seen before include "Fighting unit" , "Large Spanish fleet" , "A great fleet - Spain had one" , "Large flotilla" , "Spanish war fleet" .)

I've seen this clue in The Times.

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