n.
 the height of an object or point in relation to sea level or ground level. 
▸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.
 
  Derivative
  
  Etymology
  ME: from L. altitudo, from altus ‘high’.