blacken vs melanize

blacken and melanize both are verbs.

Word	Noun	Adjective	Verb	Adverb
blacken	No	No	Yes	No
melanize	No	No	Yes	No

As verbs, blacken and melanize are synonyms defined as:

Other synonyms of blacken include black, melanise.

blacken (verb)	melanize (verb)
make or become black	make or become black
burn slightly and superficially so as to affect color	convert into, or infiltrate with melanin