Double Under

When a single person is displaying both underboob and underbutt.

All eyes were on her when she walked into the club with the double under.

Bike Phone

A second phone that somebody carries, usually for work, or to spread out battery usage from intensive media consumption, like 2x speed podcasts, or gaming, like Pokémon Go, Fortnite.

“I don’t have to worry about running out of battery, because I text with one phone and game on my bike phone.”