[complexity] In descriptive complexity, a branch of computational complexity, FO is a complexity class of structures which can be recognized by formulas of first-order logic, and also equals the complexity class AC0. Descriptive complexity uses the formalism of logic, but does not use several key notions associated with logic such as proof ...
Foxtrot Oscar (i.e. F**k Off) (US/UK Forces)
A warm dry wind on the lee side of a mountain range. The heating and drying are due to adiabatic compression as the wind descend downslope.
• (n.) The Chinese name of Buddha.
Fish Only. Saltwater aquarium containing fish but not Live Rock or Reef animals.
Fragrance oil.
The two-character ISO 3166 country code for FAROE ISLANDS.
abbreviation: Faroe Islands (Danish islands between Iceland and
F*** Off
Fo noun The Chinese name of Buddha. 
Foldout
Fuel oil/free out
fuck off
Foreign Office (UK, WWII)
First class Open carriage
Forward Observer, a person within sight of a target who calls indirect fire or Close Air Support onto it.
Faroe Islands
acronym: furnace oil
Emplaced flamethrower/fougasse mine [SU]
Buddha (def. 1).