Second eleven go down? (7)

I believe the answer is:

subside

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'go down?' is the definition.
(subsiding is a kind of going down)

'second eleven' is the wordplay.
'second' becomes 'sub' (I can't explain this - if you can you should believe this answer much more).
'eleven' becomes 'side' (a football side).
'sub'+'side'='SUBSIDE'

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(Other definitions for subside that I've seen before include "Go down in level" , "(Of floods) go down" , "Cave in" , "Sink, settle" , "Fall back" .)

I've seen this clue in The Independent.

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