From Chinese 福 (fú, “fortunate; prosperity, good luck”), via its use as 福星 (Fúxīng, “Jupiter”) in Chinese statues of the Three Lucky Stars, picked up from c. 1935 as a nonsense word in Bill Holman's Smokey Stover comic strip, whence it was picked up by Pogo, Looney Tunes, and others. Used by Jack Speer as the name of a mock god of mimeography in the 1930s.
Popularized in computing contexts by the Tech Model Railroad Club's 1959 Dictionary of the TMRC Language, which incorporated it into a parody of the Buddhist chant om mani padme hum, possibly under the influence of WWII military slang FUBAR, which had been repopularized by Joseph Heller's Catch-22.
Meanings
(uncountable) A metasyntactic variable used to represent an unspecified entity. If part of a series of such entities, it is often the first in the series, and followed immediately by bar.
Suppose we have two objects, foo and bar.
(alt-of, slang, uncountable) Alternative letter-case form of Foo (“placeholder god”).
[page 10:] "I knew you'd be scared," Reggie laughed. "What are you doin', foo? You must be crazy. You don't scare me." "Then why did you almost fall out of that chair? I scare everyone."
[page 38:] "This is coo," said Fred. "It's almost like being there." "We are there, foo!" said Reggie as the boys slapped palms. 2020, J. Lewis Johnson, A Dark Night in the Fieldhouse:
Forms
Spelling
Features
Labels
Source
foos
Number=Plur
lexicographic
foo'
alternative
lexicographic
Relateds
foo lion (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo fighter (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo dog (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo-foo band (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo-foo (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo-foo juice (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo yung (Multiword terms containing "foo" (probably unrelated to the above etymologies)) · foo young (Multiword terms containing "foo" (probably unrelated to the above etymologies))