deterrent vs millstone

deterrent and millstone both are nouns.

Word	Noun	Adjective	Verb	Adverb
deterrent	Yes	Yes	No	No
millstone	Yes	No	No	No

As nouns, millstone is a hyponym of deterrent; that is, millstone is a word with a more specific, narrower meaning than deterrent:

deterrent: something immaterial that interferes with or delays action or progress
millstone: (figurative) something that hinders or handicaps

Other hyponyms of deterrent include albatross, bind, diriment impediment, drag, obstacle, obstruction, straitjacket.

deterrent (noun)	millstone (noun)
something immaterial that interferes with or delays action or progress	one of a pair of heavy flat disk-shaped stones that are rotated against one another to grind the grain
	any load that is difficult to carry
	(figurative) something that hinders or handicaps

deterrent (adjective)	millstone (adjective)
tending to deter