Nostril (noun)

Either of the two external openings of the nose, situated at the top of the nose.

Origin:

From the old english "nosethyrl" meaning "nose hole".

Examples:

1. He breathed in through his nostrils.
2. She pinched her nostrils shut to stop the smell.
3. The nostrils flared in anger.
4. The nostrils are the openings in the nose.
5. The nostrils are the openings through which we breathe.