Foe N Em (Foenem) is a slang term used by members of the Four Corner Hustlers (4CH) gang to refer to each other. For example, in Lud Foe's "I'm Da Man" song, he raps "Foenem pull up on yo ass you get left on - At your head like a dread, don't get clamped on -Trigger squeeze squeeze, bullets rip your Teflon." Lud Foe is essentially saying that when his fellow gang members (Foenem) pull up on you, you get killed.
On Foe N Em
On Foe N Em (ON Foenem) is a form of swearing used the Four Corner Hustlers (4CH) gang, It's similar to saying "On my brothers," "On my gang," or "On My Mama."
This term sounds very similar to On Folk Nem, which is used by members of the Folks Nation which include gangs such as the Gangster Disciples and the Black Disciples.