Answer: altazimuth

AnswerCrossword Clue
altazimuthan instrument for measuring the altitude and azimuth of heavenly bodies
altazimuthA telescope mounting that moves in azimuth (about a vertical axis) and in altitude (about a horizontal axis)
altazimuthA telescope on such a mounting
altazimuthA surveying instrument for measuring vertical and horizontal angles, resembling a theodolite but larger and more precise