Definition of pi:
(v) :
to spill or mix printing type. Also, "to
pie"
(adj) :
not part of the usual font character set; especially, non-Roman type or
symbols as opposed to standard
alphanumeric Roman type
"in computing, pi characters are entered with special combinations of keys like ctrl-alt-x, or via character sequences such as {."
(abbrev) :
pica (conventionally, 12 points = 1 pica, 6 picas = 1 inch);
piaster