What is "jew's-trump"

Jew's-harp \Jew's-harp`\, n. [Jew + harp; or possibly a corrupt. of jaw's harp; cf. G. maultrommel, lit., mouthdrum.]

1. An instrument of music, which, when placed between the teeth, gives, by means of a bent metal tongue struck by the finger, a sound which is modulated by the breath; -- called also Jew's-trump.

2. (Naut.) The shackle for joining a chain cable to an anchor.