Gei‧ger count‧er /ˈɡaɪɡə ˌkaʊntə $ -ɡər ˌkaʊntər/
noun [countable][
Date: 1900-2000;
Origin: Hans W. Geiger (1882-1945), German scientist who invented it (with Walter M. Müller)]
an instrument that finds and measures
radioactivity [TahlilGaran] Dictionary of Contemporary English ▲