6. (Mech. & Surv.) (a) An instrument by which to find a horizontal line, or adjust something with reference to a horizontal line. (b) A measurement of the difference of altitude of two points, by means of a level; as, to take a level.
7. A horizontal passage, drift, or adit, in mine. Air level, a spirit level. See Spirit level (below). — Box level, a spirit level in which a glass-covered box is used instead of a tube. — Garpenter's level, Mason's level, either the plumb level or a straight bar of wood, in which is imbedded a small spirit level. — Level of the sea, the imaginary level from which heights and depths are calculated, taken at a mean distance between high and low water. — Line of levels, a connected series of measurements, by means of a level, along a given line, as of a railroad, to ascertain the profile of the ground. — Plumb level, one in which a horizontal bar is placed in true position by means of a plumb line, to which it is at right angles. — Spirit level, one in which the adjustment to the horizon is shown by the position of a bubble in alcohol or ether contained in a nearly horizontal glass tube, or a circular box with a glass cover. — Surveyor's level, a telescope, with a spirit level attached, and with suitable screws, etc., for accurate adjustment, the whole mounted on a tripod, for use in leveling; — called also leveling instrument. — Water level, an instrument to show the level by means the surface of water in a trough, or in upright tubes connected by a pipe.
LEVEL
Lev"el, a.
1. Even; flat; having no part higher than another; having, or conforming to, the curvature which belongs to the undisturbed liquid parts of the earth's surface; as, a level field; level ground; the level surface of a pond or lake. Ample spaces o'er the smooth And level pavement. Milton.
2. Coinciding or parallel with the plane of the horizon; horizontal; as, the telescope is now level.
3. Even with anything else; of the same height; on the same line or plane; on the same footing; of equal importance; — followed by with, sometimes by to. Young boys and girls Are level now with men; the odds is gone. Shak. Everything lies level to our wish. Shak.
4. Straightforward; direct; direct; clear; open. A very plain and level account. M. Arnold.
5. Well balanced; even; just; steady; impartial; as, a level head; a level understanding. [Colloq.] " A level consideration." Shak.
6. (Phonetics)
Defn: Of even tone; without rising or falling inflection. H. Sweet. Level line (Shipbuilding), the outline of a section which is horizontal crosswise, and parallel with the rabbet of the keel lengthwise. Level surface (Physics), an equipotential surface at right angles at every point to the lines of force.