Term often used between multiple partners to alert the individual of an attack from the rear usually pertaining to a zombie outbreak.
Todd: "I'm doin' so awesome, nothin' can stop us now!!"
Jack: "TODD!! Check your crucial 6!!"
Todd: " Thanks man, that zombie almost mounted me from behind!!"
Jack: "TODD!! Check your crucial 6!!"
Todd: " Thanks man, that zombie almost mounted me from behind!!"
by Gnomerer December 21, 2010