Source : Webster's Revised Unabridged Dictionary (1913)

Pi \Pi\, v. t. [imp. & p. p. {Pied}; p. pr. & vb. n. {Pieing}.]
   (Print.)
   To put into a mixed and disordered condition, as type; to mix
   and disarrange the type of; as, to pi a form. [Written also
   {pie}.]