Pronounced- four one oh
Its actually the name of a skateboarding team that originated in McMinn County, Tennessee. And made very Popular because of the age of the youth that skated for it.
The name its self has no meaning behind it.
Although the X' between 41o stand for STRAIGHT EDGE.
The word was often yelled by the skaters from the team after landing something "big".
jon: holy cow did you just see what billy just landed?! That was sick!
(billy rolling away from the trick yells): 4x1xox
! In Ya Asshole!