Lass ate appalling condiment, perhaps? (3,4)
I believe the answer is:
'condiment perhaps?' is the definition.
(sea salt is a condiment)
'lass ate appalling' is the wordplay.
'appalling' indicates an anagram (an appalling spelling).
'lassate' anagrammed gives 'SEA-SALT'.
(Other definitions for sea salt that I've seen before include "Eat, lass! (anag) - something used when cooking" , "Condiment from the briny" .)