middle zone
/ˈmɪdl ˌzəʊn/noun
1 Poetic = torrid zone.
- Frequently with reference to Ovid..
2In handwriting: the linear area whose height and position is defined by that of lower-case letters without ascenders or descenders; the area corresponding to the x-height.
Origin
Mid 16th century; earliest use found in Arthur Golding (d. 1606), translator. From middle + zone.