The act of putting a Justin Bieber song into someone's head, thereby exposing them to at least 24 hours of pure torture.
This can be done by singing the song or just by the sheer mention of a Justin Bieber song. It can also be used as something your friend would say to you after successfully getting an awful Bieber song stuck in your head.
To have a limp or non-erect penis; usually when it is at its smallest size. Most likely derived from Justin Bieber due to possibly his young age and large ego
It's also commonly used as "bieber", then hyphenated with penis; or a synonym of penis.