Break bra -- there's bust (8)
I believe the answer is:
breather
'break' is the definition.
(I know that breather is a type of relief)
'bra there's bust' is the wordplay.
'bust' is an anagram indicator.
'bra'+'there'='brathere'
'brathere' with letters rearranged gives 'BREATHER'.
(Other definitions for breather that I've seen before include "One who inspires" , "Short pause for rest" , "Brief pause for rest" , "lung or > liver?" , "A rest from work - rather be thus" .)