/
ˈsɪmɪtri/
n.
 (pl. symmetries)
 the quality of being made up of exactly similar parts facing each other or around an axis. 
▸correct or pleasing proportion of parts.
 ▸similarity or exact correspondence.
 ▸Physics  & Mathematics  the property of being unchanged by a given operation or process.
Derivative
- symmetrize
 or symmetrise v. 
Etymology
C16: from Fr. symétrie or L. symmetria, from Gk, from sun- ‘with’ + metron ‘measure’.