Pop-up appliance (7)
I believe the answer is:
toaster
'pop-up appliance' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for toaster that I've seen before include "Machine for making brown bread?" , "Best man" , "Person with role at wedding reception" , "Device using sliced bead" , "Kitchen gadget" .)