[n] any projection that is thought to resemble an arm; "the arm of the record player"; "an arm of the sea"; "a branch of the sewer"
[n] the graduated arc that is attached to an instrument for measuring angles; "the limb of the sextant"
[n] either of the two halves of a bow from handle to tip; "the upper limb of the bow"
[n] one of the jointed appendages of an animal used for locomotion or grasping: arm; leg; wing; flipper
[n] (astronomy) the circumferential edge of the apparent disc of the sun or the moon or a planet
[n] any of the main branches arising from the trunk or a bough of a tree