This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
俽 combines 亻 (person) with 欣, which likely contributes the sound and the idea of joy or gladness. The exact historical development is uncertain.
A person 亻 beside 欣, a shape associated with joy. Imagine a person expressing gladness.
For キン, picture a person joyfully playing a kin (琴, きん) beside the 欣 component: kin -> キン.