Brimstone - Vine's Expository Dictionary of New Testament Words
Brimstone[ 1,,G2303, theion ]
originally denoted fire from heaven." It is connected with sulphur. Places touched by lightning were called theia, and, as lightning leaves a sulphurous smell, and sulphur was used in pagan purifications, it received the name of theion, Luke 17:29; Revelation 9:17-Revelation 9:18; Revelation 14:10; Revelation 19:20; Revelation 20:10; Revelation 21:8.
[ 2,,G2306, theiodes ]
akin to No. 1, signifies "brimstone-like, or consisting of brimstone," Revelation 9:17.