Foo

Part of speech: noun

Definitions

1. A nonsense word with no inherent meaning, used as a stand-in name for an unspecified person, thing or value in examples and demonstrations
2. A made-up filler term that programmers and writers use in place of a real name when the actual name does not matter
3. An arbitrary placeholder label, commonly used in computing and technical writing, that signals a generic example rather than a specific item

Etymology: The noun "foo" has a surprisingly tangled ancestry, and the most striking link runs through Chinese statuary. In Chinese temples and households, the Three Lucky Stars are represented by figures of Fu, Lu and Shou, and "fú" (福, "good fortune") is the character tied to Fuxing, the star of prosperity. Around 1935, cartoonist Bill Holman used "foo" as a meaningless word in his Smokey Stover comic strip, and it spread from there to Pogo and Looney Tunes. Jack Speer, a fan writer of the same decade, borrowed it as the name of a mock god of mimeography, the duplicating process of the time. In computing, the word gained its lasting identity through the Tech Model Railroad Club at MIT. It may also have been reinforced by the WWII slang "FUBAR", which Joseph Heller's Catch-22 had revived.