'Wormwood' definitions:

Definition of 'wormwood'

noun

Any of several low composite herbs of the genera Artemisia or Seriphidium

From: GCIDE

Wormwood \Worm"wood\, n. [AS. werm?d, akin to OHG. wermuota, wormuota, G. wermuth, wermut; of uncertain origin.] [1913 Webster]
1. (Bot.) A composite plant (Artemisia Absinthium), having a bitter and slightly aromatic taste, formerly used as a tonic and a vermifuge, and to protect woolen garments from moths. It gives the peculiar flavor to the cordial called absinthe. The volatile oil is a narcotic poison. The term is often extended to other species of the same genus. [1913 Webster]
2. Anything very bitter or grievous; bitterness. [1913 Webster]
Lest there should be among you a root that beareth gall and wormwood. --Deut. xxix. 18. [1913 Webster]
Roman wormwood (Bot.), an American weed ({Ambrosia artemisiaefolia}); hogweed.
Tree wormwood (Bot.), a species of Artemisia (probably Artemisia variabilis) with woody stems.
Wormwood hare (Zool.), a variety of the common hare ({Lepus timidus}); -- so named from its color. [1913 Webster]

Wormwood Heb. la'anah, the Artemisia absinthium of botanists. It is noted for its intense bitterness (Deut. 29:18; Prov. 5:4; Jer. 9:15; Amos 5:7). It is a type of bitterness, affliction, remorse, punitive suffering. In Amos 6:12 this Hebrew word is rendered "hemlock" (R.V., "wormwood"). In the symbolical language of the Apocalypse (Rev. 8:10, 11) a star is represented as falling on the waters of the earth, causing the third part of the water to turn wormwood.
The name by which the Greeks designated it, absinthion, means "undrinkable." The absinthe of France is distilled from a species of this plant. The "southernwood" or "old man," cultivated in cottage gardens on account of its fragrance, is another species of it.