First to return this container (3)
I believe the answer is:
pot
'this container' is the definition.
(pot is a kind of container)
'first to return' is the wordplay.
'first' becomes 'top' ('top' can be a synonym of 'first').
'to return' says the letters should be written in reverse.
'top' in reverse letter order is 'POT'.
(Other definitions for pot that I've seen before include "Receptacle" , "Kitchen utensil or slang cannabis" , "Cooking vessel or slang marijuana" , "Somewhere to go" , "Plant holder" .)