Old barrier started to get harmed (7)
I believe the answer is:
damaged
'harmed' is the definition.
(I've seen this before)
'old barrier started' is the wordplay.
'old' becomes 'aged' (similar in meaning).
'barrier' becomes 'dam' (dam is a kind of barrier).
'started' means one lot of letters go next to another.
'aged' put after 'dam' is 'DAMAGED'.
'to get' acts as a link.
(Other definitions for damaged that I've seen before include "Impaired" , "Hurt" , "Flawed, harmed" , "in poor condition" , "Harmed, injured or spoiled" .)