English Etymology From tele- + converter. Noun teleconverter (plural teleconverters) English Wikipedia has an article on:teleconverterWikipedia (photography) A secondary lens mounted between the camera and a photographic lens so as to enlarge the central part of an image obtained by the objective lens. Antonyms speedbooster Related terms teleconversionWikiwand - on Seamless Wikipedia browsing. On steroids.