mobbing
n.— «The students, all boys and football players, allegedly surrounded another student in a school hallway during lunch Nov. 20 and punched the student’s arms, chest and back as part of a practice some call “mobbing.”…Jones said police do not regard the incident as a mobbing—a term police consider to be gang-related.» —“East High students cited in hazing incident” by Lisa Schencker Salt Lake Tribune (Utah) Dec. 9, 2008. (source: Double-Tongued Dictionary)