dī​néng

incompetent

低能 dī​néng
incompetent adjective
lacking the necessary skills, capacity, or ability to perform a task or function

He has shown himself to be quite incompetent in management.

mentally deficient adjective
having low intelligence or a mental disability; extremely stupid

This rehabilitation center specializes in providing special education for children with intellectual disabilities.

Frequency

Movie subtitles
1.82 per million appears in 1% of films
Written text
0.961 per million

Sources

Definitions
CC-CEDICT