Whale's nostril (8)
I believe the answer is:
blowhole
'whale's nostril' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for blowhole that I've seen before include "Nostril of whale or dolphin on the top of its head" , "escape route from tunnel" , "Whale's nostril" , "Opening for the escape of gas or air" .)