Also see definition of "Outer" in Word Study
Outer
OUTER [isbe]
OUTER - 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.
Also see definition of "Outer" in Word Study