noun, な adjective, の adjective
Something that's not good is bad or substandard. This usage is more formal and frequently paired with other kanji compounds. Alternatively, it can refer to someone who is a delinquent, in which case it is often used as a standalone word.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
It feels like Viet kind of has bad-boy hair today, don't you think?
Substandard potato chips were sold at half price, so I bought one and ate it. Then I got diarrhea.
That delinquent girl’s grades suddenly dropped drastically and then she joined a gang.