Scrote was a term used in 2015, derived from the word "scrotum", that replaced a derogatory use of the word "balls".
It was used by Leslie "Spike" O'Malley, the sole female member of Griff's gang, when they approached Marty McFly, Jr. in the Cafe 80's and asked if he would join them on their robbery of the Hill Valley Payroll Substation.
When Marty Jr. said it could be dangerous, indicating that he had no fortitude to go along with Griff's proposal of "tonight's opportunity", Spike asked "What's wrong, McFly? You got no scrote?", before proceeding to grab Marty Jr. in that very personal place(!), lifting him up off the floor.