Like Jack's wit? (5)
I believe the answer is:
salty
'like jack's wit?' is the definition.
The answer and definition are not the same part of speech.
'like jack's wit?' is the wordplay.
I cannot quite understand how this works, but
'like' could be 'y' (similar in meaning) and 'y' is found within the answer.
'wit?' could be 'salt' (salt can mean wit or spirit) and 'salt' is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for salty that I've seen before include "Saline" , "Brackish" , "Piquant" , "Engagingly stimulating or provocative" , "Sharp (language, humour)" .)