An Etymological Dictionary of Astronomy and Astrophysics

1. The height above sea level.
   

2. The angle between an object’s position on the celestial sphere and the horizon.
   

3. Of a triangle, the perpendicular from the base to the opposite vertex.

Etymology (EN): Altitude, from L. altitudo, from altus “high”.

Etymology (PE): Farâzâ, from farâz “above, up, upon,” → height, + noun making suffix -a.