What's the difference between i.e. and e.g.?
Old English biter "bitter, sharp, cutting; angry, embittered; cruel," from Proto-Germanic *bitras- (cf. Old Saxon bittar, Old Norse bitr, Dutch bitter, Old High German bittar, German bitter, Gothic baitrs "bitter"), from PIE root *bheid- "to split" (cf. Old English bitan "to bite;" see bite (v.)). Evidently the meaning drifted in prehistoric times from "biting, of pungent taste," to "acrid-tasting." Used figuratively in Old English of states of mind and words. Related: Bitterly.
Bitterness is symbolical of affliction, misery, and servitude (Ex. 1:14; Ruth 1:20; Jer. 9:15). The Chaldeans are called the "bitter and hasty nation" (Hab. 1:6). The "gall of bitterness" expresses a state of great wickedness (Acts 8:23). A "root of bitterness" is a wicked person or a dangerous sin (Heb. 12:15). The Passover was to be eaten with "bitter herbs" (Ex. 12:8; Num. 9:11). The kind of herbs so designated is not known. Probably they were any bitter herbs obtainable at the place and time when the Passover was celebrated. They represented the severity of the servitude under which the people groaned; and have been regarded also as typical of the sufferings of Christ.
any of numerous aromatized and often alcoholic liquids containing bitter substances (chiefly alkaloids, glycosides, or complexes), used as tonics, liqueurs, appetizers, digestives, flavourings, and ingredients to add tang or smoothness to alcoholic drinks. Bitters are prepared according to secret recipes by several manufacturers using bitter herbs, leaves, fruits, seeds, or roots and sometimes alcohol or sugar. The taste is imparted by substances such as orange peel, gentian root, rhubarb root, hop flowers, quassia-wood chips, cascarilla, cinchona bark, and quinine. Aroma is provided by juniper, cinnamon, caraway, anise, nutmeg, camomile, cloves, and other flavouring agents. Bitters are usually named according to the ingredient giving the predominant flavour, such as orange bitters and peach bitters. The alcoholic strength varies but is generally about 40 percent by volume