Definitions:

1. A device consisting of electrodes sealed in a vacuum within a glass or metal enclosure. NOUN
   • The vintage amplifier uses vacuum tubes to produce a warm, rich sound favored by many audiophiles.
2. An electronic device that controls the flow of electric current in a high-vacuum emvironment. NOUN
   • Early computers relied on vacuum tubes to process information before transistors were developed.
3. Electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope. NOUN
   • The vacuum tube, with its glowing filaments and glass envelope, seved as an essential component in early radios.

Synonyms:

• discharge valve
• electron tube
• thermionic valve
• vacuum valve