(Always abbreviated to "sysop") /sis' op/ A term used in the BBS wORld fOR the operatOR of a bulletin-board system (who is usually also the owner). A common neophyte mistake on FidoNet is to address a message to "sysop" in an international echo, thus sending it to hundreds of sysops around the wORld. Contrast: system chefistratOR. (1999-10-20)