Either of the external openings of the nose; a naris.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "nostril" in a sentence
"My nostril is pulled up a little but he says it'll go down as it heals. for those of you who haven't done it yet, if the the doctor offers you for something for pain, take it!"
"It's bleeding a little periodically and my left nostril is totally swollen shut."
"One nostril is dripping what looks like grape juice onto the cell floor."