come down vs sicken

come down and sicken both are verbs.

Word	Noun	Adjective	Verb	Adverb
come down	No	No	Yes	No
sicken	No	No	Yes	No

As verbs, come down and sicken are synonyms defined as:

come down (verb)	sicken (verb)
get sick	get sick
be the essential element	make sick or ill
criticize or reprimand harshly	cause aversion in; offend the moral sense of
move downward and lower, but not necessarily all the way	upset and make nauseated
fall from clouds