acorn tube vs electron tube

acorn tube and electron tube both are nouns.

Word	Noun	Adjective	Verb	Adverb
acorn tube	Yes	No	No	No
electron tube	Yes	No	No	No

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

acorn tube: a small vacuum tube; used at high frequencies
electron tube: electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope

Other hypernyms of acorn tube include thermionic tube, thermionic vacuum tube, thermionic valve, tube, vacuum tube.

acorn tube (noun)	electron tube (noun)
a small vacuum tube; used at high frequencies	electronic device consisting of a system of electrodes arranged in an evacuated glass or metal envelope