Damaged souvenir one dropped on edge (7)
I believe the answer is:
nervous
'on edge' is the definition.
(I've seen this in another clue)
'damaged souvenir one dropped' is the wordplay.
'damaged' indicates anagramming the letters.
'one' becomes 'I' (Roman numeral).
'dropped' indicates named letters should be taken away.
'souvenir' with 'i' taken out is 'souvenr'.
'souvenr' anagrammed gives 'NERVOUS'.
(Other definitions for nervous that I've seen before include "Frightened" , "Twitchy" , "stewing" , "Fearful or apprehensive" , "Fidgety" .)