Breathe old beer covering husband (6)
I believe the answer is:
exhale
'breathe' is the definition.
(I know that exhale is a more specific form of the action breathe)
'old beer covering husband' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'beer' becomes 'ale' (type of beer).
'covering' means one lot of letters goes inside another.
'husband' becomes 'h' (abbreviation).
'ex'+'ale'='exale'
'exale' going around 'h' is 'EXHALE'.
(Other definitions for exhale that I've seen before include "Breathe out" , "produce emissions" , "Expel air from the lungs" , "Give out" , "let breath out" .)