Apply pressure to burden tradesman (7)

I believe the answer is:

plumber

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'tradesman' is the definition.
(I've seen this before)

'apply pressure to burden' is the wordplay.
'apply pressure' becomes 'p' (I can't justify this - if you can you should give a lot more credence to this answer).
'to burden' becomes 'lumber'.
'p'+'lumber'='PLUMBER'

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(Other definitions for plumber that I've seen before include "Pipe-fitter" , "tradesman" , "domestic technician" , "He repairs water pipes, installs washing machines etc" , "Repairer of pipes" .)

I've seen this clue in The Sun.

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