- noun the main office which controls all smaller offices
- A structure which houses one or more telephone switching systems. At this location, customer lines terminate and are interconnected with each other, in addition to being connected to trunks, which may also terminate there. A typical central office handles about 10,000 subscribers, each with the same area code plus first three digits of the 10 digit telephone numbers. Its abbreviation is CO. Also called telephone central office, exchange (1), local central office, or telephone exchange.
- prefix working or acting together
Information & Library Science
- abbreviation in Internet addresses, the top-level domain for Colombia
- noun an officer commanding a battalion or equivalent-sized grouping