:trit: /trit/ [by analogy with `bit'] n. One base-3 digit; the
amount of information conveyed by a selection among one of three
equally likely outcomes (see also {bit}). Trits arise, for
example, in the context of a {flag} that should actually be able
to assume *three* values --- such as yes, no, or unknown. Trits are
sometimes jokingly called `3-state bits'. A trit may be
semi-seriously referred to as `a bit and a half', although it is
linearly equivalent to 1.5849625 bits (that is,
log2(3)
bits).
-- The AI Hackers Dictionary