Everyone takes pigs round trees (7)

I believe the answer is:

sallows

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'trees' is the definition.
(sallow is a kind of tree)

'everyone takes pigs round' is the wordplay.
'everyone' becomes 'all' (all people).
'takes' is an insertion indicator (take can mean to capture or invade).
'pigs round' becomes 'sows' (I've seen this before. I am not sure about the 'round' bit.).
'all' put into 'sows' is 'SALLOWS'.

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