1. (initialism) .  chief security officer.
  2. (initialism) .  combined sewer overflow.
  3. (initialism) .  community service officer.
  4. (initialism) .  chief sustainability officer.

This is an unmodified, but possibly outdated, definition from Wiktionary and used here under the Creative Commons license. Wiktionary is a great resource. If you like it too, please donate to Wikimedia.

This entry was last updated on RefTopia from its source on 3/20/2012.