Breathing space? (4)

'breathing space' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for pore that I've seen before include "Rope around the skin-opening" , "Where sweat appears" , "Look intently" , "Small skin orifice; study" , "Rope around tiny hole" .)
(Other definitions for lung that I've seen before include "breather" , "Air bag?" , "Of sound mind" , "Respiratory organ" , "urban area" .)
This might be a double definition.
'breathing' is the first definition.
The answer and definition can be both acts as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'space?' is the second definition.
(I've seen this in another clue)
Can you help me to learn more?
(Other definitions for air that I've seen before include "Gas mixture required for breathing" , "Atmosphere, manner" , "'Tune, melody (3)'" , "Broadcast - song" , "Outward appearance" .)
'breathing space' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for respite that I've seen before include "Pause to rest" , "Short period of rest" , "Brief let-up" , "temporary delay" , "interruption" .)