frustration
frustrazioni
froos-trah-TSYOH-neh
The adjective is frustrato/a. 'Sentirsi frustrato' is very common in everyday Italian, especially in work contexts.
La frustrazione cresce quando non vedo risultati.
Frustration grows when I don't see results.
Ha espresso la sua frustrazione con un grido.
He expressed his frustration with a shout.