Twin air-intakes under a bridge (8)
I believe the answer is:
nostrils
'twin air-intakes' is the definition.
Although both the answer and definition are plural nouns, I can't see how one could define the other.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for nostrils that I've seen before include "Nose-openings" , "Openings to the nasal cavity" , "Slit Ron's nose parts" , "Openings in the nose" , "Openings in nasal cavities" .)