1. The space between the anterior edge of the nose and the lip: Hank was very proud to be growing a luxuriant mustache on his rhinarium.
2. In mammals, the extremity of the nose; especially, when hairless and habitually moist: Brenda's cat often nudges her with its rhinarium when it wants attention.
3. The area of hairless skin surrounding the nostrils in some animals: Mary's dog got in a fight with a porcupine and had some spines stuck into his rhinarium which caused a great deal of pain.