\Met`a*cen"ter\or -tre \-tre\, n. [Pref. meta- +
center.] (Hydrostatics)
The point of intersection of a vertical line through the
center of gravity of the fluid displaced by a floating body
which is tipped through a small angle from its position of
equilibrium, and the inclined line which was vertical through
the center of gravity of the body when in equilibrium.
Note: When the metacenter is above the center of gravity, the
      position of the body is stable; when below it,
      unstable.