A person who entertains people for money in public places (as by singing or dancing), usually while asking for money

In the comic book, the main character is a busker who uses their musical talent to fight crime in the city.

(anatomy) a natural hollow or sinus within the body

During the Civil War, soldiers often suffered from infections in their bodily cavities due to unsanitary conditions.

Having more than one valence, or having a valence of 3 or higher

During World War I, polyvalent vaccines were developed to protect soldiers against multiple strains of influenza.