cataphyll vs seed leaf

cataphyll and seed leaf both are nouns.

Word	Noun	Adjective	Verb	Adverb
cataphyll	Yes	No	No	No
seed leaf	Yes	No	No	No

As nouns, seed leaf is a hyponym of cataphyll; that is, seed leaf is a word with a more specific, narrower meaning than cataphyll:

cataphyll: a reduced or scarcely developed leaf at the start of a plant's life (i.e., cotyledons) or in the early stages of leaf development
seed leaf: embryonic leaf in seed-bearing plants

Other hyponyms of cataphyll include cotyledon.

cataphyll (noun)	seed leaf (noun)
a reduced or scarcely developed leaf at the start of a plant's life (i.e., cotyledons) or in the early stages of leaf development	embryonic leaf in seed-bearing plants