Underage User 

A user under the required age (usually 13) to join an online platform.

Ex.

Bob is 11. Bob joins a 13+ platform illegally. Mandy, who is 16 and is a staff member finds out and bans Bob for being an underage user.

Underage User by Henzo1 December 13, 2021

Underage User 

A person who is under a set age. "Underage User" may be used for forums, online games ect... Anywhere online where there is a set age you must be.

Ex.
Bobby is 12. Bobby joins a 13+ forum. Mandy who is 14 and a staff member finds out- Mandy banns Bobby's arse =) and did it because he was a Underage User

Underage User by Ryaa July 22, 2006

UNDERAGE USER! 

U suck like a 12 yr old girl^^

"UNDERAGE USER!"

UNDERAGE USER! by fucker August 21, 2003

underage user alert

To be yelled at anyone on forums who says something immature or stupid, suggesting a preteen poster.

Iamover18 : Liek Teletubbies r teh Rox
Sinner: UNDERAGE USER ALERT!!!!!!!!

underage user alert by Kissingtheshadows March 25, 2005