존버

Grinding through the worst with pure stubbornness — holding out no matter how bad it gets. From 존나 (intensifier, vulgar) + 버티다 (to endure/hold out). The Korean spirit of pushing through when everything tells you to quit.

존 = intensifier (vulgar) — extremely / like crazy (shortened from '존'나)

버 = to endure / hold out (shortened from '버'티다)