쩐다 /jjeon-da/
Insane / Mind-blowing
Originally meant 'reeks/smells' but evolved to mean something is outrageously impressive. Similar to 'it slaps' in English — high praise.
Examples
저 선수 진짜 쩐다
That player is absolutely insane
이 음식 쩐다 ㄹㅇ
This food literally slaps