1) placed at an extreme corner, the corner foundation stone
Part of Speech: adjective
Citing in TDNT: 1:792, 137
From G206 and G1137; belonging to the extreme corner: - chief corner.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root ἀκρογωνιαῖος; click on the second column to search for that grammatical form of the root ἀκρογωνιαῖος; click on the third column to search for that word and grammatical form; click on the total to search for the root ἀκρογωνιαῖος.