Titus 2:13

Existence surpassing the normal bounds

If we don't go by idiomatic usage (since we are after the real and not the idiom or metaphor), the literal and morphological sense is:

περιούσιον = περί (“around, beyond, over”) + οὐσία (“being, essence, substance, property”).

• περί in compounds can mean around spatially, but very often it carries the force of beyond, exceeding, in addition to.

• οὐσία from the verb εἰμί (“to be”), originally “being, existence,” later “substance, property, wealth.”

• Morphologically, περιούσιος would mean “being beyond” or “over-being,” i.e., “that which exists beyond the ordinary” or “surplus/exceeding essence.”

So, if you take it in the most literal, non-idiomatic sense, περιούσιον could be described as:

“beyond-being,” “super-being,” or “that which exists over and above.”

From there, the idiomatic “special possession” is just the conventionalized meaning — but the root picture is of existence surpassing the normal bounds.