音叉
Tuning \Tun"ing\, a. & n. from {Tune}, v. {Tuning fork} (Mus.), a steel instrument consisting of two prongs and a handle, which, being struck, gives a certain fixed tone. It is used for tuning instruments, or for ascertaining the pitch of tunes.
tuning fork n : a metal implement with two prongs that gives a fixed tone when struck; used to tune musical instruments