Search Result for "electron gun":
Wordnet 3.0

NOUN (1)

1. the electrode that is the source of electrons in a cathode-ray tube or electron microscope; consists of a cathode that emits a stream of electrons and the electrostatic or electromagnetic apparatus that focuses it; 



WordNet (r) 3.0 (2006):

electron gun
    n 1: the electrode that is the source of electrons in a cathode-
         ray tube or electron microscope; consists of a cathode that
         emits a stream of electrons and the electrostatic or
         electromagnetic apparatus that focuses it