Gins are a means for obliterating things (7)
I believe the answer is:
erasing
'for obliterating things' is the definition.
I can't judge whether this defines the answer.
'gins are a' is the wordplay.
'gins are' can be anagrammed to 'ERASING'.
However, I am not sure how the anagram is indicated.
'means' is the link.
Can you help me to learn more?
(Other definitions for erasing that I've seen before include "Getting rid of" , "Removing" , "Rubbing out" , "obliterating memory" .)