sole1
Pronunciation: /səʊl/
noun
- the undersurface of a person’s foot: the soles of their feet were nearly black with dirt
- the section forming the underside of a piece of footwear (typically excluding the heel when this forms a distinct part): the join between the upper and the sole there was mud caked between the heel and the sole
- the part of the undersurface of a person’s foot between the toes and the instep: a big blister on each heel and sole
- the undersurface of a tool or implement such as a plane or the head of a golf club.
- the floor of a ship’s cabin or cockpit.
verb

Origin:
Middle English: from Old French, from Latin solea 'sandal, sill', from solum 'bottom, pavement, sole'; compare with Dutch zool and German Sohle