Raise a glass to (5)
I believe the answer is:
toast
'raise a glass to' is the definition.
(to raise a glass to someone is to toast them)
This is all the clue.
(Other definitions for toast that I've seen before include "Health-giving" , "Food (that one can drink!)" , "Cook by radiant heat" , "It's found under marmalade and butter" , "Cheers" .)