This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
伳 combines 亻 (person) with 世, but the historical development and original meaning are uncertain.
A person 亻 beside 世 (world/generation) might suggest a person of the world, but the meaning is uncertain.
For セツ, imagine a person 亻 setting (セツ) out into the world 世: set -> セツ.