Fig.: to face an unpleasant experience with courage

The draughts is giving a very hard time to the farmers of the area, but no one is giving up. They all decided to bite the bullet and make the best of the situation

La siccità sta facendo vedere i sorci verdi ai contadini della zona, ma nessuno si arrende, tutti stringono i denti e tirano avanti come meglio possono

After losing the bet, he clenched his jaw and shaved his beloved moustaches off

Dopo aver perso la scommessa, ha stretto i denti e si è tagliato gli adorati baffi

The roller coaster makes him dizzy, but it's so much fun that he bites the bullet and down he goes

Le montagne russe gli danno le vertigini, ma sono talmente divertenti che si fa forza e si butta

It seems most plausible that this expression originated in battlefield surgery before the days of anesthesia (1844 in the U.S.A.). A surgeon about to operate on a wounded soldier would urge him to bite on a soft-lead bullet to distract him from the pain or to prevent him from screaming