snake polypody vs fern

snake polypody and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
snake polypody	Yes	No	No	No
fern	Yes	No	No	No

As nouns, fern is a hypernym of snake polypody; that is, fern is a word with a broader meaning than snake polypody:

snake polypody: epiphytic ferns with long rhizomes; tropical America
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

snake polypody (noun)	fern (noun)
epiphytic ferns with long rhizomes; tropical America	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores