ἀκρογωνιαῖος/akrogōniaios

This word describes something. It is an adjective.

This word describes an important stone in a building. This stone is either the cornerstone or the keystone
- The cornerstone was the first stone that builders laid when they started to make a stone building. It was a large stone, and the builders put it at one corner of where they were going to build the building. If they did not put it in the right place, the whole building would be crooked.
- The keystone is the top stone in an archway that builders make out of stones. The keystone is the last stone that they put in the arch, and it makes all the other stones in the arch stay in their correct place.

See: Ephesians 2:20; 1 Peter 2:6