Wormwood, in the Old Testament, is derived from a Hebrew word meaning bitterness or to curse (Strong's Concordance #H3939). It was considered cursed since it was regarded as poisonous. Given that the word is found, in the KJV Bible, seven times in seven verses (Deuteronomy 29:18, Proverbs 5:4, Jeremiah 9:15, 23:15, Lamentations 3:15, 19 and Amos 5:7) it may symbolize complete bitterness or a perfect poison. In the latter regard, it is interesting to note that the Hebrew word behind wormwood is translated as "hemlock" in Amos 6:12 (KJV).
Wormwood is actually a plant, or more precisely a low woody shrub, with small green leaves and greenish-yellow flowers. Four species of this plant, in the genus Artemisia, were known to flourish in the dry desert regions of Palestine and Syria. They are A. nilotica, A. Judaica, A. fructicosa and A. cinerea (Smith's Bible Dictionary). In modern times, A. Judaica is found only in the Sinai while A. herba-alba (also considered a wormwood plant) is common in the Holy Land (Tyndale Bible Dictionary).
The plant has a bitter taste and a strong aroma. It is sometimes Biblically equated with gall (Jeremiah 9:15, 23:15, Lamentations 3:19), a bitter poison that was offered to Jesus as he was being crucified (Matthew 27:33 - 34).
New Testament usage
In the New Testament, wormwood is found twice in a single verse.
Now the name of the star is Wormwood; and a third of the waters became wormwood; and many men died from drinking the waters because they were made bitter (Revelation 8:11, HBFV).
The word's use in Revelation is during an end-time period known as the Day of the Lord. This period, kicked off when the prophetic seventh seal is opened (Revelation 8:1), signifies God's punishment of the world's Babylonish system and those who follow it.
The wormwood of Revelation is not a plant but possibly a large meteor or star that, when it strikes the earth, makes a third of our drinkable water lethal to consume.
Absinthe, an emerald green drink with a high alcohol content, is made from A. absinthium (considered a grand wormwood herb) and other aromatic plants. The herb is native to Eurasia and North Africa, with it also being found in the United States and Canada. Although the drink was banned in America in 1912, the ban was lifted in 2007 but with restrictions.