foo
= F =
fool
foobar n.
[very common] Another widely used
metasyntactic variable; see foo for etymology. Probably
originally propagated through DECsystem manuals by Digital
Equipment Corporation (DEC) in 1960s and early 1970s;
confirmed sightings there go back to 1972. Hackers do not
generally use this to mean FUBAR in either the slang or jargon
sense. See also Fred Foobar. In RFC1639, "FOOBAR" was made
an abbreviation for "FTP Operation Over Big Address Records", but
this was an obvious backronym. It has been plausibly
suggested that "foobar" spread among early computer engineers
partly because of FUBAR and partly because "foo bar" parses in
electronics techspeak as an inverted foo signal; if a digital
signal is coded so that a positive voltage or high current
condition represents a "1", then a horizontal bar is commonly
placed over the signal label.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.