This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 甶 is uncertain. It may be an ancient variant or a rare character with unclear origins.
The shape resembles a head with a mark on the forehead, but without a clear meaning, it is best remembered as a rare character with an uncertain sense.
For フツ, imagine a rare, fuzzy creature with a marked head: fuzzy -> フツ, and the creature is as obscure as this kanji.