Damage around broken timer shows impairment (9)
I believe the answer is:
detriment
'impairment' is the definition.
(I know that detriment is a type of impairment)
'damage around broken timer' is the wordplay.
'damage' becomes 'dent' (dent is a kind of damage).
'around' is an insertion indicator.
'broken' indicates anagramming the letters.
'timer' is an anagram of 'trime'.
'dent' placed around 'trime' is 'DETRIMENT'.
'shows' acts as a link.
(Other definitions for detriment that I've seen before include "State of being harmed or damaged" , "Damage, loss" , "Possible loss" , "Harm, damage" , "hurt" .)