This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
俒 combines 亻 (person) with 完, but the exact historical development and original meaning are uncertain.
A person 亻 beside 完 (complete) might suggest a person who is whole or perfect, but the actual meaning is unclear.
For コン, imagine a person 亻 completing 完 a con (コン) job: con -> コン.