pantograph vs mechanical device

pantograph and mechanical device both are nouns.

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

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

pantograph: mechanical device used to copy a figure or plan on a different scale
mechanical device: mechanism consisting of a device that works on mechanical principles

pantograph (noun)	mechanical device (noun)
mechanical device used to copy a figure or plan on a different scale	mechanism consisting of a device that works on mechanical principles