splint vs mechanical device

splint and mechanical device both are nouns.

Word	Noun	Adjective	Verb	Adverb
splint	Yes	No	Yes	No
mechanical device	Yes	No	No	No

As nouns, mechanical device is a hypernym of splint; that is, mechanical device is a word with a broader meaning than splint:

splint: an orthopedic mechanical device used to immobilize and protect a part of the body (as a broken leg)
mechanical device: mechanism consisting of a device that works on mechanical principles

splint (noun)	mechanical device (noun)
an orthopedic mechanical device used to immobilize and protect a part of the body (as a broken leg)	mechanism consisting of a device that works on mechanical principles
a thin sliver of wood

splint (verb)	mechanical device (verb)
support with a splint