The Jargon File (version 4.4.7, 29 Dec 2003):
n. Two bits; also as taste. Syn. crumb, quarter. See nybble.
The Free On-line Dictionary of Computing (18 March 2015):
(Or tayste /tayst/) Silly suggested term for
two binary digits.
The term "quarter" has also been suggested, referring to the
US 25-cent coin. This was once equal in value to two of the
eight "bits" - pie-slice-shaped "pieces of eight" - into which
Spanish silver crowns were cut to make change.