The Collaborative International Dictionary of English v.0.48:
Sole \Sole\ (s[=o]l), n. [AS. sole, fr. L. soolea (or rather an
assumed L. sola), akin to solumround, soil, sole of the foot.
Cf. Exile, Saloon, Soil earth, Sole the fish.]
1. The bottom of the foot; hence, also, rarely, the foot
The dove found no rest for the sole of her foot.
Hast wandered through the world now long a day,
Yet ceasest not thy weary soles to lead. --Spenser.
2. The bottom of a shoe or boot, or the piece of leather
which constitutes the bottom.
The "caliga" was a military shoe, with a very thick
sole, tied above the instep. --Arbuthnot.
3. The bottom or lower part of anything, or that on which
anything rests in standing. Specifially:
(a) (Agric.) The bottom of the body of a plow; -- called
also slade; also, the bottom of a furrow.
(b) (Far.) The horny substance under a horse's foot, which
protects the more tender parts.
(c) (Fort.) The bottom of an embrasure.
(d) (Naut.) A piece of timber attached to the lower part
of the rudder, to make it even with the false keel.
(e) (Mining) The seat or bottom of a mine; -- applied to
horizontal veins or lodes.
Sole leather, thick, strong, used for making the soles of
boots and shoes, and for other purposes.