keystone /noun/ प्रधान सिद्धांत; मेहराब के बीच की पत्थर; डाट; डाट का पत्थर; चाप-पाषाण; मेहराब का पत्थर; मुख्य आधार;
Synonym entablature;
English Dictionary:
1. Keystone [n.]
- The central or topmost stone of an arch. This in some
styles is made different in size from the other voussoirs, or projects,
or is decorated with carving. See Illust. of Arch.