n.
Pronunciation: ' si-m ə -tr ē
Function: noun
Inflected Form: plural -tries
Etymology: Latin symmetria, from Greek, from symmetros symmetrical, from syn- + metron measure ― more at MEASURE
Date: 1563
1 : balanced proportions also : beauty of form arising from balanced proportions
2 : the property of being symmetrical especially : correspondence in size, shape, and relative position of parts on opposite sides of a dividing line or median plane or about a center or axis ― compare BILATERAL SYMMETRY , RADIAL SYMMETRY
3 : a rigid motion of a geometric figure that determines a one-to-one mapping onto itself
4 : the property of remaining invariant under certain changes (as of orientation in space, of the sign of the electric charge, of parity, or of the direction of time flow) ― used of physical phenomena and of equations describing them