\Ge*ot"ro*pism\, n. [Gr. ge`a, gh^, the earth + ? to
turn.] (Biol.)
A disposition to turn or incline towards the earth; the
influence of gravity in determining the direction of growth
of an organ.
Note: In plants, organs which grow towards the center of the
      earth are said to be positively geotropic, and those
      growing in the opposite direction negatively geotropic.
      In animals, geotropism is supposed by some to have an
      influence either direct or indirect on the plane of
      division of the ovum.