Meaning

noun (mathematics) an attribute of a shape or relation; exact reflection of form on opposite sides of a dividing line or plane

noun balance among the parts of something

noun (physics) the property of being isotropic; having the same value when measured in different directions

originFrom Latin symmetria, from Ancient Greek συμμετρία (summetría), from σύμμετρος (súmmetros, “symmetrical”), from σύν (sún, “with”) + μέτρον (métron, “measure”). By surface analysis, sym- + -metry.

Etymology from Wiktionary, CC BY-SA 3.0