handicap vs millstone

handicap and millstone both are nouns.

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

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

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

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

handicap (noun)	millstone (noun)
advantage given to a competitor to equalize chances of winning	one of a pair of heavy flat disk-shaped stones that are rotated against one another to grind the grain
something immaterial that interferes with or delays action or progress	any load that is difficult to carry
the condition of being unable to perform as a consequence of physical or mental unfitness	(figurative) something that hinders or handicaps

handicap (verb)	millstone (verb)
injure permanently
put at a disadvantage
attempt to forecast the winner (especially in a horse race) and assign odds for or against a contestant