What the toast may do when you're out of bed after a drink (3,2)
I believe the answer is:
pop up
'what the toast may do when you're' is the definition.
The definition suggests a singular noun but the answer is not.
'out of bed after a drink' is the wordplay.
'out of bed' becomes 'up' (synonyms).
'after' is a charade indicator (letters next to each other).
'a drink' becomes 'pop' (fizzy pop).
'up' put after 'pop' is 'POP-UP'.
Can you help me to learn more?
(Other definitions for pop up that I've seen before include "Appear suddenly or unexpectedly" , "Appear (like toast?)" , "which may interrupt computer user" , "book for youngster" , "three-dimensional picture book" .)