alt·az·i·muth / alˈtazəmə[unvoicedth]/ • n. 1. (also altazimuth mount or mounting) Astron. a telescope mounting that moves in azimuth (about a vertical axis) and in altitude (about a horizontal axis). Compare with equatorial mount. ∎  (also altazimuth telescope) a telescope on such a mounting.2. a surveying instrument for measuring vertical and horizontal angles, resembling a theodolite but larger and more precise.

altazimuth (astron.) instrument for determining the altitude and azimuth. XIX. f. ALT(ITUDE) + AZIMUTH.