Deviation of the line of the vertical

Related to Deviation of the line of the vertical: Dissociated Vertical Deviation
the difference between the actual direction of a plumb line and the direction it would have if the earth were a perfect ellipsoid and homogeneous, - caused by the attraction of a mountain, or irregularities in the earth's density.

See also: deviation

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.