Webster's 1828 Dictionary
LEVELING
ppr. 1. Making level or even.
2. Reducing to an equality of condition.
LEVELING
n.The art or practice of finding a horizontal line, or of ascertaining the different elevations of objects on the surface of the earth; in other words, the difference in the distance of objects from the center of the earth.
Webster's 1913 Dictionary
LEVELING
Lev "el *ing, n. Etym: [Written also levelling.]
1. The act or operation of making level.
2. (Surveying )
Defn: The art or operation of using a leveling instrument for finding a horizontal line, for ascertaining the differences of level between different points of the earth's surface included in a survey, for establishing grades, etc. , as in finding the descent of a river, or locating a line of railroad. Leveling instrument. See Surveyor's level, under Level, n. -- Leveling staff, a graduated rod or staff used in connection with a leveling instrument for measuring differences of level between points.
New American Oxford Dictionary
leveling rod
lev el ing rod ▶noun a graduated pole with a movable marker, held upright and used with a surveying instrument to measure differences in elevation. Also called leveling pole, leveling staff.
leveling screw
lev el ing screw ▶noun a screw for adjusting part of a machine or instrument to a precise level.
Oxford Dictionary
leveling rod
lev el ing rod ▶noun a graduated pole with a movable marker, held upright and used with a surveying instrument to measure differences in elevation. Also called leveling pole, leveling staff.
The Wordsmith Dictionary