El dinero extra que dejas al mesero por su servicio, aparte de la cuenta. En México dar propina es una costumbre importante y dejar el 10% se considera lo mínimo aceptable, aunque el estándar real entre gente considerada es el 15-20%.

Thinking too much about something until you drive yourself crazy with your own brain without finding a solution. It's the torturous mental loop that won't leave you alone and has you going in circles about the same thing with no way out.

To be in deep trouble or a hopeless situation with no way out. When you're fried, things have gone so wrong that there's no fixing it — time to accept your fate.

Keeping someone as a romantic backup option without committing but without letting them go either. Like having a player on the bench: they don't play but you don't release them just in case you need them.