pteridophyte vs fern

pteridophyte and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
pteridophyte	Yes	No	No	No
fern	Yes	No	No	No

As nouns, fern is a hyponym of pteridophyte; that is, fern is a word with a more specific, narrower meaning than pteridophyte:

pteridophyte: plants having vascular tissue and reproducing by spores
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

Other hyponyms of pteridophyte include fern ally.

pteridophyte (noun)	fern (noun)
plants having vascular tissue and reproducing by spores	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores