Tube with a cone-shaped opening (6)
I believe the answer is:
funnel
'tube with a cone-shaped opening' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for funnel that I've seen before include "Convey" , "Kind of tube for pouring wide at top and narrow at bottom" , "Tube with a cone-shaped opening" , "Passage for escape of smoke" , "Chimney; pourer" .)