thermionic tube vs thermionic valve

thermionic tube and thermionic valve both are nouns.

Word	Noun	Adjective	Verb	Adverb
thermionic tube	Yes	No	No	No
thermionic valve	Yes	No	No	No

As nouns, thermionic tube and thermionic valve are synonyms defined as:

thermionic tube and thermionic valve: electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope

Other synonyms of thermionic tube include electron tube, thermionic vacuum tube, tube, vacuum tube.

thermionic tube (noun)	thermionic valve (noun)
electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope	electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope