"hindmost part of an animal," Old English tægl, tægel "a tail," from Proto-Germanic *tagla- (cognates: Old High German zagal, German Zagel "tail," dialectal German Zagel "penis," Old Norse tagl "horse's tail," Gothic tagl "hair"), from PIE *doklos, from suffixed form of root *dek- (2) "something long and thin" (referring to such things as fringe, lock of hair, horsetail; cognates: Old Irish dual "lock of hair," Sanskrit dasah "fringe, wick"). According to OED, the primary sense, at least in Germanic, seems to have been "hairy tail," or just "tuft of hair," but already in Old English the word was applied to the hairless "tails" of worms, bees, etc. But Buck writes that the common notion is of "long, slender shape." As an adjective from 1670s.Meaning "reverse side of a coin" (opposite the side with the head) is from 1680s; that of "backside of a person, buttocks" is recorded from c.1300; slang sense of "pudenda" is from mid-14c.; that of "woman as sex object" is from 1933, earlier "act of copulation" with a prostitute (1846). Of descending strokes of letters, from 1590s.Tails "coat with tails" is from 1857. The tail-race (1776) is the part of a mill race below the wheel. To turn tail "take flight" (1580s) originally was a term in falconry. The image of the tail wagging the dog is attested from 1907. Another Old English word for "tail" was steort (see stark).
2
"limitation of ownership," a legal term, early 14c. in Anglo-French; late 13c. in Anglo-Latin, in most cases a shortened form of entail.
v.
1520s, "attach to the tail," from tail, n.1. Meaning "move or extend in a way suggestive of a tail" is from 1781. Meaning "follow secretly" is U.S. colloquial, 1907, from earlier sense of "follow or drive cattle." Related: Tailed; tailing. Tail off "diminish" is attested from 1854.
1. entail（有力切en(=intensive) + tail (=cut)） vt.使必需；使承担；限定不动产的继承人 n.限定继承 entailment n.继承人之限定 Applying for college entails a great deal of paperwork. 申请入大学需要做大量的书面工作。
3. detail n.细节，细目；详情；详述；（美术中）细部（描绘）v.详述；（为特殊任务）派遣 *de(=down,intensive) detailed report 详细报道 go /enter into details 详述，逐一细说 in detail 详细地，仔细地 five soldiers were detailed to guard the bridge. 一名士兵被派去守卫大桥。