G0204–ἀκρογωνιαῖος–akrogōniaios

And are built upon the foundation of the apostles and prophets, Jesus Christ himself being the chief corner stone;

ἀκρογωνιαίου akrogōniaiou “[the] cornerstone”

Wherefore also it is contained in the scripture, Behold, I lay in Sion a chief corner stone, elect, precious: and he that believeth on him shall not be confounded.

ἀκρογωνιαῖον akrogōniaion “cornerstone”