() A glass vessel, varying in size, open at the bottom and closed at the top like a bell, and having a knob or handle at the top for lifting it. It is used for a great variety of purposes; as, with the air pump, and for holding gases, also for keeping the dust from articles exposed to view.
BELL JAR
Meaning of BELL JAR in English
Webster's English dictionary. Английский словарь Webster. 2012