seed cake vs seedcake

seed cake and seedcake both are nouns.

Word	Noun	Adjective	Verb	Adverb
seed cake	Yes	No	No	No
seedcake	Yes	No	No	No

As nouns, seed cake and seedcake are synonyms defined as:

seed cake and seedcake: a sweet cake flavored with sesame or caraway seeds and lemon

seed cake (noun)	seedcake (noun)
a sweet cake flavored with sesame or caraway seeds and lemon	a sweet cake flavored with sesame or caraway seeds and lemon