[The mountains] their broad bare backs upheave
Into the clouds.
Milton.
3. The outward or upper part of a thing, as opposed to the inner or lower part; as, the back of the hand, the back of the foot, the back of a hand rail.
Methought Love pitying me, when he saw this,
Gave me your hands, the backs and palms to kiss.
Donne.
4. The part opposed to the front; the hinder or rear part of a thing; as, the back of a book; the back of an army; the back of a chimney.
5. The part opposite to, or most remote from, that which fronts the speaker or actor; or the part out of sight, or not generally seen; as, the back of an island, of a hill, or of a village.
6. The part of a cutting tool on the opposite side from its edge; as, the back of a knife, or of a saw.