gymnosperm vs phanerogam

gymnosperm and phanerogam both are nouns.

Word	Noun	Adjective	Verb	Adverb
gymnosperm	Yes	No	No	No
phanerogam	Yes	No	No	No

As nouns, phanerogam is a hypernym of gymnosperm; that is, phanerogam is a word with a broader meaning than gymnosperm:

gymnosperm: plants of the class Gymnospermae having seeds not enclosed in an ovary
phanerogam: plant that reproduces by means of seeds not spores

Other hypernyms of gymnosperm include seed plant, spermatophyte.

gymnosperm (noun)	phanerogam (noun)
plants of the class Gymnospermae having seeds not enclosed in an ovary	plant that reproduces by means of seeds not spores