myxomycete vs slime mould

myxomycete and slime mould both are nouns.

Word	Noun	Adjective	Verb	Adverb
myxomycete	Yes	No	No	No
slime mould	Yes	No	No	No

As nouns, slime mould is a hypernym of myxomycete; that is, slime mould is a word with a broader meaning than myxomycete:

myxomycete: a slime mold of the class Myxomycetes
slime mould: a naked mass of protoplasm having characteristics of both plants and animals; sometimes classified as protoctists

Other hypernyms of myxomycete include slime mold.

myxomycete (noun)	slime mould (noun)
a slime mold of the class Myxomycetes	a naked mass of protoplasm having characteristics of both plants and animals; sometimes classified as protoctists