/op/ n. 1. In England and Ireland, common verbal abbreviation for `operator', as in system operator. Less common in the U.S., where sysop seems to be preferred. 2. [IRC] Someone who is endowed with privileges on IRC, not limited to a particular channel. These are generally people who are in charge of the IRC server at their particular site. Sometimes used interchangeably with CHOP. Compare sysop.