Tieso (en. Stiff)

/ˈtjeso/

Slang Meanings

To be very serious or to be angry.
Don't be stiff, we're here to have fun.
No te pongas tieso, estamos aquí para divertirnos.
Referring to someone who behaves strictly.
The new boss is a stiff who doesn't accept any jokes.
El nuevo jefe es un tieso que no acepta ninguna broma.