Concussion vessels of great antiquity, occurring in many sizes and grades of sound throughout their history. Traditionally they have consisted of a pair of round metal plates, usually slightly convex to create a resonant hollow, sounded by striking together. In modern orchestral and jazz music, cymbals are often played as percussion instruments, suspended and struck with drumsticks or wire brushes.

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300041897