grimace vs lower

grimace and lower both are nouns.

Word	Noun	Adjective	Verb	Adverb
grimace	Yes	No	Yes	No
lower	Yes	Yes	Yes	No

As verbs, lower is a hyponym of grimace; that is, lower is a word with a more specific, narrower meaning than grimace:

grimace: contort the face to indicate a certain mental or emotional state
lower: look angry or sullen, wrinkle one's forehead, as if to signal disapproval

Other hyponyms of grimace include squinch, squint, wince, smile, frown, glower, lour, screw up, mop, mow, pout.

grimace (noun)	lower (noun)
a contorted facial expression	the lower of two berths

grimace (adjective)	lower (adjective)
	the bottom one of two

grimace (verb)	lower (verb)
contort the face to indicate a certain mental or emotional state	make lower or quieter
	set lower
	cause to drop or sink
	move something or somebody to a lower position
	look angry or sullen, wrinkle one's forehead, as if to signal disapproval