diode vs duodiode

diode and duodiode both are nouns.

Word	Noun	Adjective	Verb	Adverb
diode	Yes	No	No	No
duodiode	Yes	No	No	No

As nouns, duodiode is a hyponym of diode; that is, duodiode is a word with a more specific, narrower meaning than diode:

diode: a thermionic tube having two electrodes; used as a rectifier
duodiode: an electron tube having two diodes in the same envelope, with either a common cathode or separate cathodes.

diode (noun)	duodiode (noun)
a semiconductor that consists of a p-n junction	an electron tube having two diodes in the same envelope, with either a common cathode or separate cathodes.
a thermionic tube having two electrodes; used as a rectifier