protozoon vs protoctist

protozoon and protoctist both are nouns.

Word	Noun	Adjective	Verb	Adverb
protozoon	Yes	No	No	No
protoctist	Yes	No	No	No

As nouns, protoctist is a hypernym of protozoon; that is, protoctist is a word with a broader meaning than protozoon:

protozoon: any of diverse minute acellular or unicellular organisms usually nonphotosynthetic
protoctist: any of the unicellular protists

protozoon (noun)	protoctist (noun)
any of diverse minute acellular or unicellular organisms usually nonphotosynthetic	any of the unicellular protists