Burning, scorch, burnt, volcanic (Sodom)
Heap, submersion (Gomorrah)
Strong's #H5467, #G4670, #H6017
Sodom and Gomorrah, like Admah, Zeboim, and Zoar, were Biblically considered "cities of the plain" (Genesis 10:19). They were located in a fertile valley, south of the Dead Sea, which in modern times is partially covered with water.
The two sinful cities, as well as three others of the plain, experienced the wrath of Chedorlaomer's forces in the first series of battles mentioned in the Bible (Genesis 14). Their attempt to lure the enemy into the slime pits of the valley of Siddim failed miserably.
The troops led by Sodom were forced to retreat, leaving their cities open to extensive looting by the victorious confederation of kings. It took a small but powerful army led by Abraham to stop the slaughtering and pillaging.
Congratulated on his victory by the city's king, Abraham is also greeted by the mysterious king of Salem named Melchizedek (Genesis 14:17 - 18).
Fire and brimstone
The grievous sins of Sodom, Gomorrah (and surrounding area), which included same-gender sex, cried out for God's judgment. In spite of Abraham's intercession to have the cities spared (Genesis 18), they were destroyed with brimstone (a highly flammable substance) and fire.
The unique and complete annihilation of several cities of the plain (Deuteronomy 29:23) took place one year before the miraculous birth of Abraham's son Isaac (Genesis 18 - 19). God did, however, mercifully spare Zoar because of a special request made by Lot (Genesis 19:17 - 22).
Interestingly, the destruction of the sinful cities such as Gomorrah are not only mentioned by Josephus (Antiquities of the Jews, chapters 9 and 11) but also in the Koran (sura liv.).
The two sinful cities are sometimes used to symbolize some of man's worst sins and God's righteous judgment of such perverse behavior.
Revelation's Two Witnesses will be killed at their end of their ministry. Their bodies will be seen in Jerusalem, a city whose spiritual state is likened to those who inhabited Sodom (Revelation 11:8).
Genesis 13:10, 13
And Lot lifted up his eyes, and beheld all the plain of Jordan, that it was well watered every where, before the Lord destroyed Sodom and Gomorrah, even as the garden of the Lord, like the land of Egypt, as thou comest unto Zoar . . .
And the Lord said, If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.
Genesis 19:24 - 25
Then the Lord rained upon Sodom and upon Gomorrah brimstone and fire from the Lord out of heaven;
And he overthrew those cities, and all the plain, and all the inhabitants of the cities, and that which grew upon the ground.
Symbolic and Prophetic
Except the Lord of hosts had left unto us a very small remnant, we should have been as Sodom, and we should have been like unto Gomorrah.
Matthew 10:14 - 15
And whosoever shall not receive you (Jesus' twelve disciples he sent out on a training mission), nor hear your words, when ye depart out of that house or city, shake off the dust of your feet.
Verily I say unto you, It shall be more tolerable for the land of Sodom and Gomorrah in the day of judgment, than for that city.
Jude 1:6 - 7
And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
Even as Sodom and Gomorrah, and the cities about them in like manner, giving themselves over to fornication, and going after strange flesh, are set forth for an example, suffering the vengeance of eternal fire.
And their dead bodies shall lie in the street of the great city, which spiritually is called Sodom and Egypt, where also our Lord was crucified.