To do something really over the top,extreme,crazy or wild although it can by used in many contexts.
Yo that nigga went up to him and snuffed
him in the face son, that niggas wildin.
Yo that bitch got drunk and started wildin, she sucked off three niggas.
Yo she put him on punishment for three month, she wildin.
Yo them niggas shot up the party with the tech nines son, they were wildin.