A kind of telescope mounting in which one of the two axes the telescope turns about is pointed vertically, and the other horizontally. The first axis is the azimuth axis, and the second is the elevation axis.
A telescope on an altazimuth mounting must usually rotate around both axes simultaneously, to follow celestial objects across the sky as the Earth rotates. For telescopes not too large or too powerful, a human being can usually operate an altazimuth mounting well enough for visual observations. Several modern commercial amateur telescopes have altazimuth mountings which are motor-driven and computer controlled.

This definition is in context to Telescope. See more contextual defintions for Altazimuth Mounting.