A sound clause, but potentially damaging (5)
I believe the answer is:
claws
'a sound clause but potentially damaging' is the definition.
I can't tell whether this definition defines the answer.
'a sound clause' is the wordplay.
'a sound' indicates a 'sounds like' (homophone) clue.
'clause' is a homophone of 'CLAWS'.
Can you help me to learn more?
(Other definitions for claws that I've seen before include "Talons" , "Grasping limbs, of a crustacean, say" , "beastly offensive" .)