Metacenter \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.

Source: Webster's Revised Unabridged Dictionary (1913)