escapement vs mechanical device

escapement and mechanical device both are nouns.

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

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

escapement: mechanical device that regulates movement
mechanical device: mechanism consisting of a device that works on mechanical principles

escapement (noun)	mechanical device (noun)
mechanical device that regulates movement	mechanism consisting of a device that works on mechanical principles