out'-er: This adjective is used 12 times by Ezekiel of the outside court of the temple. In Matthew we find it 3 times (8:12; 22:13; 25:30) in "outer darkness" (to skotos to exoteron), which typifies the utter darkness of the doom of the lost.
The International Standard Bible Encyclopedia
Outer
The International Standard Bible Encyclopedia, James Orr (1915). Public domain, from the CrossWire SWORD module.