Pile on to player (7)

I believe the answer is:

reactor

'pile' is the definition.
(term for a nuclear reactor)

'on to player' is the wordplay.
'on' becomes 're' (regarding).
'to player' becomes 'actor' (synonyms).
're'+'actor'='REACTOR'

(Other definitions for reactor that I've seen before include "I swing back" , "Heart of a nuclear power station" , "(Nuclear) powerplant" , "Nuclear energy generator" , "one liable to have a meltdown if things go disastrously?" .)

I've seen this clue in The Independent.

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