heighten vs subtilize

heighten and subtilize both are verbs.

Word	Noun	Adjective	Verb	Adverb
heighten	No	No	Yes	No
subtilize	No	No	Yes	No

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

Other hyponyms of heighten include subtilise.

heighten (verb)	subtilize (verb)
increase the level of	make more subtle or refined
become more extreme	make (senses) more keen
make more extreme; raise in quantity, degree, or intensity	mark fine distinctions and subtleties, as among words
make more intense, stronger, or more marked
make (one's senses) more acute
increase the height of