terrestrial telescope n (General Physics) a telescope for use on earth rather than for making astronomical observations. Such telescopes contain an additional lens or prism system to produce an erect image. Compare astronomical telescope Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014