Lexical Definition

‎θεῖον‎ theîon (thi'-on) sulfur G:N-N
probably neuter of ‎θεῖος‎ (in its original sense of flashing)

brimstone.

Usage: 5 forms in 14 verses
Form Translated As     In Verse(s)
θεῖον brimstone Luke.17.29Rev.9.17
θείῳ brimstone Rev.14.10Rev.19.20
with brimstone Rev.21.8
θείω sulphur LXX.Job.18.15
θείου brimstone Rev.9.18
of sulfur Rev.20.10
sulphur LXX.Isa.30.33
θείον sulphur LXX.Gen.19.24LXX.Deut.29.23LXX.Ps.11.6LXX.Isa.34.9LXX.Ezek.38.22

Abbott-Smith

θεῖον, -ου, τό, [in LXX; Ge 19:24, De 29:23 (22), Jb 18:15, Ps 10(11):7*, Is 30:33 34:9, Ez 38:22 (גׇּפְרִית), III Mac 2:5*;]
brimstone: Lk 17:29(LXX), Re 9:17, 18 14:10 19:20 20:10 21:8.†

Abbott-Smith References

Book Refs
Genesis 19:24
Deuteronomy 29:22 · 29:23
Job 18:15
Psalms 11:7*
Isaiah 30:33 · 34:9
Ezekiel 38:22
Luke 17:29
Revelation 9:17 · 9:18 · 14:10 · 19:20 · 20:10 · 21:8

Liddell-Scott-Jones

θεῖον,

__AEpic dialect θέειον (in [Refs 8th c.BC+] θήϊον), τό, brimstone, used to fumigate and purify, δέπας.. ἐκάθηρε θεείῳ [Refs 8th c.BC+]; δεινὴ δὲ θεείου γίγνεται ὀδμή, from a thunderbolt, [Refs 8th c.BC+]; ἐν δὲ θεείου πλῆτο, of a ship struck by lightning, [Refs 8th c.BC+]; ἐμβαλόντες πῦρ ξὺν θ. [LXX+5th c.BC+]; as a natural product, [Refs 5th c.BC+]; opposed to πεπυρωμένον, [Refs 1st c.AD+]; compare θεάφιον, θέαφος. (Perh. cognate with θύω, θυμιάω, Latin suffire.)

LSJ Scripture Refs: LXX.Gen.19.24