Here brat disturbed rest (8)
I believe the answer is:
breather
'rest' is the definition.
(I know that breather is a type of rest)
'here brat disturbed' is the wordplay.
'disturbed' indicates an anagram (the order of letters is disturbed).
'here'+'brat'='herebrat'
'herebrat' with letters rearranged gives 'BREATHER'.
(Other definitions for breather that I've seen before include "Short rest between bouts of exercise" , "Rather be having a rest - inhale" , "state" , "An informal break - inhale and exhale" , "A rest - lung?" .)