When food won't go down quickly? (4)
I believe the answer is:
fast
'quickly?' is the definition.
(synonyms)
'when food won't go down' is the wordplay.
I cannot really see how this works, but
'when' could be 'as' (eg 'when I walked' means 'as I walked') and 'as' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for fast that I've seen before include "Can't move" , "Quick - don't eat" , "Rapidly; tight" , "Unlikely to run" , "Unable to move" .)