Open

The term used in electronics to signify no connection between things. Obviously you’d assume that most things aren’t connected because everything can’t be connected to everything so open is really used to signify there is no connection between two things where there is likely to be a connection. For example, a standard light switch may be in a state of closed (where the switch is “on”) or open (where it is “off”). In audio patch bays open is a type of normalling distinction that means there is no normal, or no connection between the two points in question.