Volcano peak (4)
I believe the answer is:
cone
'volcano peak' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for cone that I've seen before include "Volcano peak" , "Figure (for traffic control?)" , "Hollow object associated with ice cream and motorways" , "may obstruct lane" , "Ice-cream cornet" .)