Digest can't aid digestive aid (7)
I believe the answer is:
antacid
'digestive aid' is the definition.
(I've seen this in another clue)
'digest can't aid' is the wordplay.
'can't aid' can be anagrammed to 'ANTACID'.
Though, I am not clear how the anagram is indicated.
Can you help me to learn more?
(Other definitions for antacid that I've seen before include "Medicine counteracting gastric juices" , "Substance used to treat stomach upsert" , "Stomach drug" , "Indigestion remedy" , "calming agent" .)