point-contact diode vs diode

point-contact diode and diode both are nouns.

Word	Noun	Adjective	Verb	Adverb
point-contact diode	Yes	No	No	No
diode	Yes	No	No	No

As nouns, diode is a hypernym of point-contact diode; that is, diode is a word with a broader meaning than point-contact diode:

point-contact diode: a semiconductor rectifier that uses the barrier formed between a specially prepared semiconductor surface and a metal point to produce the rectifying action.
diode: a semiconductor that consists of a p-n junction

Other hypernyms of point-contact diode include crystal rectifier, junction rectifier, semiconductor diode.

point-contact diode (noun)	diode (noun)
a semiconductor rectifier that uses the barrier formed between a specially prepared semiconductor surface and a metal point to produce the rectifying action.	a semiconductor that consists of a p-n junction
	a thermionic tube having two electrodes; used as a rectifier