Beehive (4)
(Other definitions for oven that I've seen before include "kitchen fixture" , "Cooking appliance" , "Small furnace" , "Place for burning" , "Liquid oxygen; salmon" .)
'beehive' is the definition.
(I know that skep is a type of beehive)
This is the entire clue.
(Another definition for skep that I've seen is " Straw beehive".)