Pertinaz (en. Pertinacious)

/peɾti'nas/

Slang Meanings

It is used to describe a person who does not yield in their ideas.
That guy is quite pertinacious, he won't accept that he's wrong.
Ese tipo es bien pertinaz, no acepta que está equivocado.
Describes a situation that is not easily resolved.
The problem is pertinacious, there's no way to solve it quickly.
El problema es pertinaz, no hay manera de solucionarlo rápido.