What can make salt last? (7)
I believe the answer is:
anagram
'last?' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
I don't understand how the rest of the clue works.
(Other definitions for anagram that I've seen before include "Word play" , "Type of word puzzle" , "Jumbling of letters" , "'Master' of 'stream', say" , "There's confusion among characters" .)