The comparative form of exo (outside), meaning more outer, most outer, or the uttermost exterior. Used exclusively in the phrase "outer darkness" (to skotos to exoteron) in Matthew 8:12, 22:13, and 25:30 to describe the place of exclusion from the kingdom feast.
The "outer darkness" of exoteros is the antithesis of the wedding feast — the warm, lit, joyful interior of God's presence. Jesus uses it three times in Matthew, each time in contexts of exclusion: the unfaithful servant, the improperly clothed wedding guest, and those who rejected the invitation. The imagery is spatial and emotional: to be cast into outer darkness is to be expelled from belonging, from light, from the community of the redeemed. It is the ultimate poverty — not just deprivation of resources but of relationship. The gospel's urgency is partly this: the door will close (Matthew 25:10).