Emily Dickinson Lexicon

LIMB, n. [lim; Sax. lim; Dan. and Sw. lem; L. limbus, edge or border, extremity; limes, limit, coinciding perhaps with W. llem, llym, sharp, or llamu, to leap. The sense of limb is from shooting or extending.]

1. Edge or border. This is the proper signification of the word; but in this sense it is limited chiefly to technical use, and applied to the sun, moon, or a star, to leaf, to quadrant, &c. We say, the sun or moon is eclipsed on its northern limb. But we never say, the limb of a board, of a tract of land or water, &c.
2. In anatomy, and in common use, an extremity of the human body; a member; a projecting part; as the arm or leg; that is, a shoot.
3. The branch of a tree; applied only to a branch of same size, and not to a small twig.
4. In botany, the border or upper spreading part of a mono-petalous corol. – Martyn.