spreader vs mechanical device

spreader and mechanical device both are nouns.

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

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

spreader: a mechanical device for scattering something (seed or fertilizer or sand etc.) in all directions
mechanical device: mechanism consisting of a device that works on mechanical principles

spreader (noun)	mechanical device (noun)
a hand tool for spreading something	mechanism consisting of a device that works on mechanical principles
a mechanical device for scattering something (seed or fertilizer or sand etc.) in all directions