\Qui"pu\, n.; pl. {Quipus}. [Peruv. quipu a knot.]
A contrivance employed by the ancient Peruvians, Mexicans,
etc., as a substitute for writing and figures, consisting of
a main cord, from which hung at certain distances smaller
cords of various colors, each having a special meaning, as
silver, gold, corn, soldiers. etc. Single, double, and triple
knots were tied in the smaller cords, representing definite
numbers. It was chiefly used for arithmetical purposes, and
to register important facts and events. [Written also
{quipo}.] --Tylor.

      The mysterious science of the quipus . . . supplied the
      Peruvians with the means of communicating their ideas
      to one another, and of transmitting them to future
      generations.                             --Prescott.