triode vs thermionic tube

triode and thermionic tube both are nouns.

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

As nouns, thermionic tube is a hypernym of triode; that is, thermionic tube is a word with a broader meaning than triode:

triode: a thermionic vacuum tube having three electrodes; fluctuations of the charge on the grid control the flow from cathode to anode which makes amplification possible
thermionic tube: electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope

Other hypernyms of triode include electron tube, thermionic vacuum tube, thermionic valve, tube, vacuum tube.

triode (noun)	thermionic tube (noun)
a thermionic vacuum tube having three electrodes; fluctuations of the charge on the grid control the flow from cathode to anode which makes amplification possible	electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope