I. noun — [ mass noun] 1. the height of an object or point in relation to sea level or ground level • flight data including airspeed and altitude
• [ count noun]
flying at altitudes over 15,000 feet.
2. great height • the mechanism can freeze at altitude.
[Astronomy] the apparent height of a celestial object above the horizon, measured in angular distance.
[Geometry] the length of the perpendicular line from a vertex to the opposite side of a figure.
II. derivatives altitudinal /altɪˈtjuːdɪn(ə)l / adjective
– origin late Middle English: from Latin altitudo, from altus ‘high’.