What does foobar mean?

Foo is the canonical metasyntactic variable, commonly used to represent an as-yet-unspecified term, value, process, function, destination or event but seldom a person (see Ned Baker, below). It might also be an abbreviation for "File Or Object". It is sometimes combined with bar to make foobar. This suggests that foo may have originated with the World War II slang term fubar, as an acronym for fucked/fouled/"fixed" up beyond all recognition/repair, although the Jargon File makes a reasonably good case that foo predates fubar. Foo was also used as a nonsense word in the surrealistic comic strip Smokey Stover that was popular in the 1940s and 1950s. See also Foo fighter for more foo etymology, as well as RFC 3092.