I have to go back - damage is obvious (7)
I believe the answer is:
evident
'obvious' is the definition.
(similar in meaning)
'i have to go back damage' is the wordplay.
'i have' becomes 'I've' (contraction of 'I have').
'to go back' says the letters should be written in reverse.
'damage' becomes 'dent' (dent is a kind of damage).
'ive' back-to-front is 'evi'.
'evi'+'dent'='EVIDENT'
'is' acts as a link.
(Other definitions for evident that I've seen before include "Obvious, may be plainly seen" , "Obvious - 1 across" , "Comprehensible - manifest" , "Quite obvious, easy to see" , "Visible - plain" .)