Gulp down (6)
I believe the answer is:
ingest
'gulp down' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ingest that I've seen before include "Take nourishment into the body" , "Take in with tinges" , "Consume food" , "Absorb, assimilate" , "How to take courses" .)