My Latin is really rusty, so I had to look this one up. YOLO (the acronym for "you only live once") is a first conjugation regular verb. It's often used as a hashtag on Twitter by people expressing their wild and dangerous lifestyles.
It was also used by the ancient Romans. For example, in his history of Rome, Livy wrote about one of the early heroes of the republic, Horatius Cocles. In the late Sixth Century B.C., the army of Lars Porsena invaded Rome. It attempted to cross a bridge into the city. Cocles stood on that bridge and personally halted the enemy advance. Livy writes:
So he shouted to them to break down the bridge by sword or fire, or by whatever means they could, he would meet the enemies' attack so far as one man could keep them at bay. He advanced to the head of the bridge. Amongst the fugitives, whose backs alone were visible to the enemy, he was conspicuous as he fronted them armed for fight at close quarters. The enemy were astounded at his preternatural courage. Two men were kept by a sense of shame from deserting him - Sp. Lartius and T. Herminius - both of them men of high birth and renowned courage. With them he sustained the first tempestuous shock and wild confused onset, for a brief interval. Then, whilst only a small portion of the bridge remained and those who were cutting it down called upon them to retire, he insisted upon these, too, retreating. Looking round with eyes dark with menace upon the Etruscan chiefs, he challenged them to single combat, and reproached them all with being the slaves of tyrant kings, and whilst unmindful of their own liberty coming to attack that of others. For some time they hesitated, each looking round upon the others to begin. At length shame roused them to action, and raising a shout they hurled their javelins from all sides on their solitary foe. He caught them on his outstretched shield, and with unshaken resolution kept his place on the bridge with firmly planted foot. They were just attempting to dislodge him by a charge when the crash of the broken bridge and the shout which the Romans raised at seeing the work completed stayed the attack by filling them with sudden panic. Then Cocles said, "Tiberinus, holy father, I pray thee to receive into thy propitious stream these arms and this thy warrior. #YOLO!" So, fully armed, he leaped into the Tiber, and though many missiles fell over him he swam across in safety to his friends: an act of daring more famous than credible with posterity.
-via Joe Carter