lprm — Cancel print jobs
lprm cancels print jobs that have been queued for printing. If no arguments are supplied, the current job on the default printer is canceled. You can specify one or more job ID numbers to cancel those jobs, or use the – option to cancel all jobs.
$ lprm — Cancel the current job on default printer.
$ lprm -P prn2 — Cancel the current job on printer PRN2.
$ lprm 100 200 — Cancel jobs with id 100 and 200.
Read: man lprm