limb

noun

1. one of the jointed appendages of an animal used for locomotion or grasping: arm, leg, wing, flipper
2. any of the main branches arising from the trunk or a bough of a tree
3. (astronomy) the circumferential edge of the apparent disc of the sun or the moon or a planet
4. either of the two halves of a bow from handle to tip"the upper limb of the bow"
5. the graduated arc that is attached to an instrument for measuring angles"the limb of the sextant"
6. any projection that is thought to resemble a human arm"the arm of the record player"