noun
: a positive lens for producing intense heat by converging the sun's rays approximately to the principal focus of the lens the point of convergence being a very small image of the sun
noun
: a positive lens for producing intense heat by converging the sun's rays approximately to the principal focus of the lens the point of convergence being a very small image of the sun
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012