altitude

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The height of a thing above a reference level, especially above sea level or above the earth's surface. See Synonyms at elevation.
2. n. A high location or area.
3. n. Astronomy The angular distance of a celestial object above the horizon.
4. n. Mathematics The perpendicular distance from the base of a geometric figure to the opposite vertex, parallel side, or parallel surface.
5. n. High position or rank.

Century Dictionary and Cyclopedia

1. n. Space extended upward; height; the degree or amount of elevation of an object above its foundation, the ground, or a given level; the amount or distance by which one object is higher than another: as, the altitude of a mountain or a cloud.
2. n. The elevation of a point, star, or other object above the horizon, measured by the arc of a vertical intercepted between such point and the horizon. Altitude is either apparent or true. Apparent altitude is that which appears by observations made at any place on the surface of the earth; true altitude, that which results by correcting the apparent for refraction, parallax, and dip of the horizon.
3. n. An elevation or height; anything extending far upward.
4. n. Highest point or degree; full elevation.
5. n. Elevation of spirit; haughty air: in this sense generally used in the plural.

Wiktionary

1. n. The height measured from sea level up to any given point.
2. n. A vertical distance.
3. n. geometry The distance measured perpendicularly from a figure's vertex to the opposite side of the vertex.
4. n. astronomy The angular distance of a heavenly body above our Earth's horizon.

GNU Webster's 1913

1. n. Space extended upward; height; the perpendicular elevation of an object above its foundation, above the ground, or above a given level, or of one object above another.
2. n. (Astron.) The elevation of a point, or star, or other celestial object, above the horizon, measured by the arc of a vertical circle intercepted between such point and the horizon. It is either true or apparent; true when measured from the rational or real horizon, apparent when from the sensible or apparent horizon.
3. n. (Geom.) The perpendicular distance from the base of a figure to the summit, or to the side parallel to the base
4. n. Height of degree; highest point or degree.
5. n. Height of rank or excellence; superiority.
6. n. colloq. Elevation of spirits; heroics; haughty airs.

WordNet 3.0

1. n. angular distance above the horizon (especially of a celestial object)
2. n. elevation especially above sea level or above the earth's surface
3. n. the perpendicular distance from the base of a geometric figure to the opposite vertex (or side if parallel)