B, jargon> (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)