noun

• A beetroot soup that can be served hot or cold, usually with sour cream.
• Any similar sour soup made of other ingredients such as sorrel, cabbage, hogweed
• (telecommunications) Acronym of battery feed, overvoltage protection, ringing, signalling, coding, hybrid, test. (the set of functions performed by a subscriber line interface circuit (SLIC) in the line card of a telecommunication system providing plain old telephone service)