Webster's Revised Unabridged Dictionary · 1913

Slope

Slope , noun

[Formed (like abode from abide) from Old English slipen. See Slip, v. i.]

1.
An oblique direction; a line or direction including from a horizontal line or direction; also, sometimes, an inclination, as of one line or surface to another.
2.
Any ground whose surface forms an angle with the plane of the horizon.
buildings the summit and slope of a hill. — Macaulay
Under the slopes of Pisgah. — Deut. iv. 49. (Rev. Ver.)
3.
The part of a continent descending toward, and draining to, a particular ocean; as, the Pacific slope.

A slope, considered as descending, is a declivity; considered as ascending, an acclivity.

Collocations (1)
Slope of a plane (Geometry) , the direction of the plane; as, parallel planes have the same slope.

Slope , adjective

Sloping.
Down the slope hills. — Milton
A bank not steep, but gently slope. — Bacon

Slope , adverb

In a sloping manner. [Obsolete] — Milton

Slope , transitive verb

To form with a slope; to give an oblique or slanting direction to; to direct obliquely; to incline; to slant; as, to slope the ground in a garden; to slope a piece of cloth in cutting a garment.

Slope , intransitive verb

1.
To take an oblique direction; to be at an angle with the plane of the horizon; to incline; as, the ground slopes.
2.
To depart; to disappear suddenly. [Slang]