Turn in, having wandered back to have a quick meal (6)
I believe the answer is:
devour
'meal' is the definition.
(thesaurus)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for devour that I've seen before include "Eat hungrily and quickly" , "Consume voraciously" , "Consume greedily" , "Guzzle" , "Eat (food) hungrily" .)