separatist vs fissiparous

separatist is a noun but fissiparous is not a noun.

Word	Noun	Adjective	Verb	Adverb
separatist	Yes	Yes	No	No
fissiparous	No	Yes	No	No

As adjectives, separatist and fissiparous are synonyms defined as:

separatist and fissiparous: having separated or advocating separation from another entity or policy or attitude

Other synonyms of separatist include breakaway.

separatist (noun)	fissiparous (noun)
an advocate of secession or separation from a larger group (such as an established church or a national union)

separatist (adjective)	fissiparous (adjective)
having separated or advocating separation from another entity or policy or attitude	reproducing by fission
	having separated or advocating separation from another entity or policy or attitude