Search

the height of anything above a given planetary reference plane, especially above sea level on earth.
extent or distance upward; height.
Astronomy. the angular distance of a heavenly body above the horizon.
Geometry.

the perpendicular distance from the vertex of a figure to the side opposite the vertex.
the line through the vertex of a figure perpendicular to the base.

Usually, altitudes. a high place or region:
mountain altitudes.
high or important position, rank, etc.
Contemporary Examples

It measures air speed—not ground speed, but the speed of the airplane at altitude.
Air France 447 Report: How the Plane Went Down Clive Irving July 4, 2012

Thunderstorms at that altitude, the Times of London reports, can have the “energy of nuclear explosions.”
7 Theories on the Crash of Flight 447 The Daily Beast June 1, 2009

Once acclimatized, the teams will fly to 87° south, where they will spend further time acclimatizing to the altitude.
Prince Harry Proves He Is The Coolest Royal As he Prepares To Walk To the South Pole Tom Sykes November 12, 2013

Were its speed and altitude settled by then, or still uncertain?
The Worst Place in the World for MH370 to Go Missing Clive Irving April 4, 2014

It has three sensors which track steps, acceleration, and altitude.
Can I Lose Weight Playing Video Games? Alec Kubas-Meyer January 13, 2014

Historical Examples

It dropped to an altitude of only a few hundred feet and turned and went back over the ground it had just crossed.
Astounding Stories, February, 1931 Various

From their altitude of four thousand feet, they could see the Denver.
The Solar Magnet Sterner St. Paul Meek

The rocs had better range and altitude than any planes of equal hauling power.
The Sky Is Falling Lester del Rey

Long before the funeral train had reached the top of the altitude.
The Shadow of a Crime Hall Caine

For every 900 feet of altitude the height of the mercury is about one inch less.
Reading the Weather Thomas Morris Longstreth

noun
the vertical height of an object above some chosen level, esp above sea level; elevation
(geometry) the perpendicular distance from the vertex to the base of a geometrical figure or solid
(astronomy, nautical) Also called elevation. the angular distance of a celestial body from the horizon measured along the vertical circle passing through the body Compare azimuth (sense 1)
(surveying) the angle of elevation of a point above the horizontal plane of the observer
(often pl) a high place or region
n.

late 14c., from Latin altitudinem (nominative altitudo) “height, altitude,” from altus “high” (see old).
altitude
(āl’tĭ-td’)

The height of an object or structure above a reference level, usually above sea level or the Earth’s surface.

Astronomy The position of a celestial object above an observer’s horizon, measured in degrees along a line between the horizon (0°) and the zenith (90°). Unlike declination and celestial latitude—the corresponding points in other celestial coordinate systems—the altitude of star or other celestial object is dependent on an observer’s geographic location and changes steadily as the sky passes overhead due to the rotation of the Earth. See more at altazimuth coordinate system.

Mathematics The perpendicular distance from the base of a geometric figure, such as a triangle, to the opposite vertex, side, or surface.