sb. [a. late L. extensor, agent-n. f. extendĕre to EXTEND.]
1. A muscle that serves to extend or straighten out any part of the body. Opposed to flexor.
[1706. Phillips (ed. Kersey), Extensor Digitorum Communis … a Muscle of the Fingers.]
1713. Derham, Phys. Theol., V. ii. (1747), 286, note. The peronæus Longus helps to … direct the Power of the other Extensors towards the Ball of the great Toe.
1748. Hartley, Observ. Man, I. ii. 245. The Limbs have both long and short Flexors and Extensors.
1870. Rolleston, Anim. Life, 14. The long radial extensor of the metacarpus.
2. attrib. in extensor-muscle; also extensor-surface, the surface of a bone to which the extensor muscles are attached.
1830. R. Knox, Béclard’s Anat., 317. The contrary takes place with respect to the extensor muscles.
1859. Darwin, Orig. Spec., vi. (1873), 139. This flank-membrane is furnished with an extensor muscle.
1881. Mivart, Cat, 94. Its anterior or extensor surface is grooved for the passage of tendons.
