When food won't go down quickly? (4)
I believe the answer is:
fast
'quickly?' is the definition.
(I know that quickly can be written as fast)
'when food won't go down' is the wordplay.
I cannot quite see how this works, but
'when' could be 'as' (eg 'when I walked' means 'as I walked') and 'as' is found within the answer.
This explanation may well be incorrect...
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" .)