from
Jargon File (4.4.4, 14 Aug 2003)
balloonian variable
n.
[Commodore users; perh. a deliberate phonetic mangling of boolean
variable?] Any variable that doesn't actually hold or control state,
but must nevertheless be declared, checked, or set. A typical
balloonian variable started out as a flag attached to some environment
feature that either became obsolete or was planned but never
implemented. Compatibility concerns (or politics attached to same) may
require that such a flag be treated as though it were {live}.