tailpiece

noun

1. 1.An appendage or appendix.
2. 2.An element, often triangular, to which the strings of a violin, guitar, etc. are attached at the lower end of an instrument.
3. 3.A short joist between a header and a wall.
4. 4.The part of a telescope containing the adjusting device for the eyepiece, etc.
5. 5.The part of a lock that transmits motion from the hub to the latch bolt.