What is Tartarus?

The word "Tartarus" appears once in the Bible — embedded in a verb. The verb is ταρταρόω (tartaroō, G5020), a NT hapax legomenon at 2 Peter 2:4. The word is borrowed from Greek mythology, where Tartarus is the deepest part of the underworld, below Hades, where the Titans were imprisoned by Zeus. Peter retools the term for a biblical purpose: a custodial holding-place for rebel angels.

The single verse

εἰ γὰρ ὁ θεὸς ἀγγέλων ἁμαρτησάντων οὐκ ἐφείσατο, ἀλλὰ σειραῖς ζόφου ταρταρώσας παρέδωκεν εἰς κρίσιν τηρουμένους "For if God did not spare angels who sinned, but having cast them into Tartarus in chains of gloom, handed them over, kept for judgment" — 2 Peter 2:4 (TAGNT)

The verbs do work. ταρταρώσας (G5020, aorist active participle) — "having cast into Tartarus." σειραῖς ζόφου (G4577 + G2217) — "in chains of gloom"; both σειρά ("chain") and ζόφος ("gloom") are NT rarities, with σειρά itself a hapax. παρέδωκεν (G3860, aorist active indicative) — "he handed over." τηρουμένους (G5083, present passive participle) — "being kept." The grammar packages a one-way trip: sinned (aorist), thrown (aorist), handed over (aorist), being kept (present passive — ongoing custody).

Jude 6 describes the same population in parallel terms but does not use the word ταρταρόω:

ἀγγέλους τε τοὺς μὴ τηρήσαντας τὴν ἑαυτῶν ἀρχὴν ἀλλ᾽ ἀπολιπόντας τὸ ἴδιον οἰκητήριον, εἰς κρίσιν μεγάλης ἡμέρας δεσμοῖς ἀϊδίοις ὑπὸ ζόφον τετήρηκεν "and angels who did not keep their own domain but abandoned their proper dwelling — for the judgment of the great day, in eternal chains under gloom, he has kept" — Jude 1:6 (TAGNT)

Same judgment-realm, same gloom (ζόφον), same custody verb (τετήρηκεν, perfect active indicative — "he has kept," locking the action into completed-with-ongoing-results state). Tartarus is named only by Peter; the population it holds is described by both.

Tartarus is not the abyss

The New Testament names a second custodial space — ἄβυσσος (abyssos, G12, "abyss"). It is mentioned 9 times. The two terms never appear in the same verse.

Demons in the Synoptic exorcisms petition not to be sent to the abyss: παρεκάλουν αὐτὸν ἵνα μὴ ἐπιτάξῃ αὐτοῖς εἰς τὴν ἄβυσσον ἀπελθεῖν (Luk 8:31, "they begged him not to command them to depart into the abyss"). The demons fear the abyss as a future destination — they are not in it now. The angels of 2 Peter 2:4 are already in Tartarus. Different beings, different geography, different custodial status.

The embedding-space neighborhoods confirm the distinction. ἄβυσσος clusters with depth-words and sea-words and with the Hebrew תְּהוֹם (tehom, H8415, "the deep"). ταρταρόω clusters with dungeon and penal vocabulary. The two semantic neighborhoods do not intersect.

Tartarus is not the lake of fire

The third custodial space is the lake of fire — λίμνη τοῦ πυρός (limnē tou pyros, G3041 + G4442). It appears 5 times, all in Revelation: 19:20; 20:10, 14, 15; 21:8.

The lake of fire is the eschatological endpoint. Tartarus is the eschatological holding cell. The angels in Tartarus are kept εἰς κρίσιν ("for judgment," 2 Pe 2:4) and εἰς κρίσιν μεγάλης ἡμέρας ("for the judgment of the great day," Jud 6) — they have not yet been judged. Their final destination is implied but not named in those verses; the parallel language in Mat 25:41 places "the devil and his angels" in τὸ πῦρ τὸ αἰώνιον ("the eternal fire") prepared for them.

Three distinct judgment-geographies

The full geography:

Three distinct prisons, three distinct populations, zero NT verses fusing any two of them. The text is more careful with its eschatological geography than the popular conflation that uses "hell" as a single word for all four.

Why Peter chose the word ταρταρόω

Peter writes to readers who knew Greek mythology. By using ταρταρόω he draws on an existing cultural picture: the deepest pit, where the most dangerous beings are imprisoned. He retools the term to describe what Genesis 6 implies and what the early Jewish reading of Genesis 6 (preserved in 1 Enoch 10's Watchers narrative) developed in detail: that some angels rebelled, and that those rebels are now under custodial restraint awaiting judgment. The word borrows the picture; the theology is biblical, paralleled in Jude 6 and consistent with Mat 25:41.

The choice does not canonize Greek mythology. Peter does not name Titans. He names angels (ἀγγέλων ἁμαρτησάντων, "angels who sinned"). He uses Tartarus the way an English writer might use "dungeon" — a borrowed term for a familiar idea, not an endorsement of the mythology that produced it.

What the text does not say

The text does not say Tartarus is the same place as the abyss. It does not say Tartarus is the same place as the lake of fire. It does not say the demons of the Synoptic exorcisms are the same beings as the angels in Tartarus. It does not narrate the moment those angels were thrown there. It does not list their names. It says: there are angels who sinned, they are bound, they are kept for judgment, the place where they are kept is called Tartarus, and the judgment is still ahead.

For the full chained-vs-roaming grammar, the geography table, and the empirical knockout — that the same noun δεσμός ("chain") is used of the bound angels (Jud 6) and of the demoniac who broke the chains (Luk 8:29) — see Demons vs. Fallen Angels — What Does the Text Say?. For the OT background and the LXX shift, see The Silence and the Storm and "Between the Testaments" — From Silence to Storm.