With effort carry round pole — getting breather (4)
I believe the answer is:
lung
'breather' is the definition.
(I've seen this before)
'with effort carry' is the wordplay.
'with' means one lot of letters goes inside another.
'effort' becomes 'n' (I can't explain this - if you can you should give a lot more credence to this answer).
'carry' becomes 'lug' (lugging is a kind of carrying).
'n' put within 'lug' is 'LUNG'.
'round pole getting' 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 lung that I've seen before include "Respiratory organ" , "One of a pair of organs in the ribcage" , "Of sound mind" , "Organ used for breathing" , "Pulmonary organ" .)