ircu/KILL
Forcefully disconnects a client.
/KILL <nick> :<reason>
Parameter <reason> can be at most 160 chars long (TOPICLEN). The oper must have the privilege LOCAL_KILL to kill local clients, and privilege KILL to kill clients on other servers. When the target user cannot be found, nick chasing is used when to attempt to find the current nick of the user last using the nick specified.
