constraint vs brake pad

constraint and brake pad both are nouns.

Word	Noun	Adjective	Verb	Adverb
constraint	Yes	No	No	No
brake pad	Yes	No	No	No

As nouns, brake pad is a hyponym of constraint; that is, brake pad is a word with a more specific, narrower meaning than constraint:

constraint: a device that retards something's motion
brake pad: one of the pads that apply friction to both sides of the brake disk

constraint (noun)	brake pad (noun)
the act of constraining; the threat or use of force to control the thoughts or behavior of others	one of the pads that apply friction to both sides of the brake disk
a device that retards something's motion
the state of being physically constrained