lún​wéi

degenerate into

沦为 (淪為) lún​wéi
degenerate into verb
to sink down to or be reduced to a lower or inferior state or position

That country used to be very wealthy, but it has now fallen into being one of the poorest in the world.

Frequency

Movie subtitles
1.07 per million appears in 1% of films
Written text
4.82 per million

Sources

Definitions
CC-CEDICT