protozoon vs protozoan

protozoon and protozoan both are nouns.

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

As nouns, protozoon and protozoan are synonyms defined as:

protozoon and protozoan: any of diverse minute acellular or unicellular organisms usually nonphotosynthetic

protozoon (noun)	protozoan (noun)
any of diverse minute acellular or unicellular organisms usually nonphotosynthetic	any of diverse minute acellular or unicellular organisms usually nonphotosynthetic

protozoon (adjective)	protozoan (adjective)
	of or relating to the Protozoa