The process of adapting to the decrease in oxygen concentration at a specific altitude. A number of changes must take place for the body to operate with decreased oxygen. These changes include increasing the depth of respiration; increasing the pressure in the pulmonary arteries, forcing blood into portions of the lung that are normally not used at [..]

Altitude sickness occurs at high altitude. So what is high altitude?Altitude is defined on the following scale:High altitude: 8,000 - 12,000 feet (2,438 - 3,658 meters);Very high altitude: 12,000 - 18,000 feet (3,658 - 5,487 meters); andExtremely high altitude: 18,000+ feet (5,500+ meters).Most people can go up to 8,000 feet (2,438 meters) with min [..]

Vertical distance above sea-level.

late 14c., from Latin altitudinem (nominative altitudo) "height, altitude," from altus "high" (see old).

height above the earth or a given reference point.

The angular distance of an object above the horizon.

the distance above sea level. Read more in the NG Education Encyclopedia

elevation especially above sea level or above the earth's surface; "the altitude gave her a headache" the perpendicular distance from the base of a geometric figu [..]

Height expressed in units of distance above a reference plane, usually above mean sea level or above ground.

n. Vertical distance or elevation above any point or base-level, as the sea.

height above sea-level.

Height in space of an object or point relative to sea level or ground level.

Length from the uppermost point of a triangle to the line opposite.

Height expressed as the distance above a reference point, which is normally sea level or ground level.Source: NOAA-NWS ERH.

Altitude is the height of an area, measured from sea level.

(n) - the height of a celestial object above the horizon

The height above sea level or above the earth’s surface.

The angle measured from the horizon to a celestial object.

the height of the land 

Height of the land above sea level.

Height of an object in the atmosphere above sea level.

The height of the motor in reference to sea level. Standard altitude is 3300 feet, or 1000 meters. Sometimes written as 3300 FASL (feet above sea level).

distance above sea level.

the perpendicular distance measured from the base of a figure to the highest point of the figure. amplitude

Angular distance between the horizon and a given object, measured along a vertical circle.

(n) elevation especially above sea level or above the earth's surface(n) the perpendicular distance from the base of a geometric figure to the opposite vertex (or side if parallel)(n) angular dis [..]

How high a place is above sea level.

The height expressed in units of distance above a reference plane, usually above mean sea level or above ground level.

The distance measured in feet, above mean sea level. Due to variations in terrain, air traffic control measures altitude as above mean sea level rather than above the ground. If you are interested in the height of aircraft above a particular location to assess potential noise impact, then local elevation should be taken into account when considerin [..]

Height, usually with respect to the terrain below (radar altitude, feet above closest dirt) or fixed earth reference (barometric altitude, feet above mean sea level); Symbols: h; Typical Units: ft; Dimensions: Length;

Vertical distance above sea-level or the earth's surface.

The height of a thing or place measured Above Ground Level or from Mean Sea Level.

A vertical distance measured from a known level on the surface of a Planet or other celestial body.

Height expressed as the distance above a reference point, which is normally sea level or ground level.

the angular distance of a celestial body above the viewers horizon.

Used in celestial navigation, it is the angle a celestial body makes with a point on the horizon vertically below this object. Historically, altitude was measured with an astrolabe, a cross staff, a b [..]

The angle a celestial body makes with the horizon.

the angle between the horizon and a celestial body. In practice, the celestial navigator will consult tables to estimate the azimuth and altitude of each star line he will attempt, and preset the sext [..]

The angle a celestial body makes with the horizon.

The vertical elevation of a location above sea level.

the arc of a vertical circle between the horizon and a point or body on the Celestial Sphere.

Height expressed as the distance above a reference point, which is normally sea level or ground level.

n. "(astro.) altitude," s.v. altitude OED. KEY: altitude@n

n 65 altitude 60 altitudes 5

1. 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; as, the altitude of a mountain, or of a bird above the top of a tree. 2. <astronomy> The elevation of a point, or star, or other celestial object, above the horizon, measure [..]

You wouldn't think there would be any dispute about this; it should simply mean how high you are.  But there is a small problem:  Standard altimeters work by measuring barometric pressure.  Befor [..]

Height, usually with respect to the terrain below (radar altitude, feet above closest dirt) or fixed earth reference (barometric altitude, feet above ...

The angle between the chord line of the wing of an aircraft and the relative wind.

  Height above ground level.

  Height about mean sea level - 0 feet.

The height at which an aircraft flies.

Height expressed in units of distance above a reference plane, usually above mean sea level or above ground.

Height, usually with respect to the terrain below (radar altitude, feet above closest dirt) or fixed earth reference (barometric altitude, feet above mean sea level); Symbols: h; Typical Units: ft; Di [..]

For each flight tracked on Flightradar24 the calibrated altitude reported from the aircraft, which is a pressure-derived value, is displayed. Extended Mode S data

Altitude is the elevation of an object from a known level. In the United States and the UK aviation altitude is usually measured in feet. Everywhere else in the world the altitude is measured in metre [..]

The vertical distance from a given level ( sea level) to an aircraft in flight.

Height

is the height of anything above given a planetary reference plane. In astronomy the angular distance of a heavenly body above the horizon.

First, find your azimuth. Next, the Altitude (or elevation) is the angle between the Earth's surface (horizon) and the sun, or object in the sky. Altitudes range from -90° (straight down below the horizon, or the nadir) to +90° (straight up above the horizon or the Zenith) and 0° straight at the horizon. definition courtesy of: What Is and S [..]

THE HEIGHT OF WHICH THE AIRCRAFT FLIES ABOVE SEA LEVEL

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

(above 3,500 ft.), adjustments may be needed in baking, cooking time, temperature and recipes. For example: • Water boils at 212° F below 2,000 ft. and more quickly from 3,000 to 10,000 ft. (208°-194° [..]

A measure of height of an object, usually with reference to the earth&#39;s surface, or sea level.

The height of the something above sea level. It is usually measured in feet or metres. Sea level is an altitude of 0m.

Height expressed as the distance above a reference point, which is normally sea level or ground level.

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

Height expressed as the distance above a reference point, which is normally sea level or ground level. Anemometer

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level. ALTOCUMULUS

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

elevation above or below a reference datum, as defined in Federal Information Processing Standard 70-1. See also elevation.

In meteorology,

In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level.

The perpendicular distance between the bases, or between the vertex and the base, of a solid or plane figure.

The vertical distance of an aircraft or object above a given reference, such as ground or sea level. Additional reference information may be obtained via Airborne Environment Classification per MIL-HD [..]

The height of a point on the land above sea level.

Altitude is basically height and is used in anti-doping for the purposes of the Athlete Biological Passport. Altitude can affect an athlete’s blood variables e.g. red blood cell count. The World Health Organisation defines anything over 1000m as being at altitude.