可能来自 tap,轻拍，轻扣。后用于指暗示，指点，告密等，同时，轻拍某人肩膀常用于表示 鼓励，友善，后引申词义小费，并有人据此逆构出 TIP,缩写自 to insure promptitude,为保证服 务速度（而给小费）。
tip 尖端，尖点，倾斜，倾覆，倾倒
词源同 top,顶部，顶端。引申词义尖端，尖点，后用于指倾斜，倾覆，倾倒等。
英文词源
tip
tip: English has three distinct words tip, two of them possibly related. Tip ‘extremity’ [15] was probably borrowed from Old Norse typpi. This was descended from prehistoric Germanic *tupp- ‘upper extremity’ (source also of English top and toupee). Tip ‘touch lightly’ [13] (as in ‘tip-and-run cricket’) may have been borrowed from Low German tippen, although it could be the same word as tip ‘extremity’ (from the notion of ‘just touching something with the tip of something else’).
It was used in 17th-century underworld argot for ‘give’ (as in ‘tip someone the wink’), and this evolved in the 18th century to ‘give a gratuity’. The antecedents of tip ‘overturn’ [14] (originally tipe) are not known, although the fact that it first appeared in northern dialects suggests that it may have been borrowed from a Scandinavian language. The derived tipsy [16] denotes etymologically ‘liable to fall over’. => top, toupee; tipsy
tip (v.1)
c. 1300, "to knock down, overturn, topple, knock askew" (transitive), of uncertain origin, possibly from Scandinavian (compare Swedish tippa "to tip, dump"), or from a special use of tip (n.). Intransitive sense of "to fall over, be overturned" is from mid-15c. Related: Tipped; tipping. To tip the scales at "weigh (so much" is from 1879. Tipping point attested by 1972. To tip (one's) hand "reveal one's intentions" is from 1907, an image from poker-playing.
tip (n.1)
c. 1400, "extreme end of something, top of something round or pointed, metal attachment to the end of something," from Middle Low German or Middle Dutch tip "utmost point, extremity, tip" (compare German zipfel, a diminutive formation); or from a Scandinavian source (compare Old Norse typpi).
tip (v.2)
"give a small present of money to," c. 1600, originally "to give, hand, pass," thieves' cant, perhaps from tip (v.3) "to tap." The meaning "give a gratuity to" is first attested 1706. The noun in this sense is from 1755; the noun meaning "piece of confidential information" is from 1845; and the verb in the sense "give private information to" is from 1883.
The popularity of the tale of the word's supposed origin as an acronym in mid-18th century English taverns seems to be no older than Frederick W. Hackwood's 1909 book "Inns, Ales and Drinking Customs of Old England," where it was said to stand for To insure promptitude (in the form to insure promptness the anecdote is told from 1946). A reviewer of the book in the "Athenaeum" of Oct. 2, 1909, wrote, "We deprecate the careless repetition of popular etymologies such as the notion that "tip" originated from an abbreviated inscription on a box placed on the sideboard in old coaching-inns, the full meaning of which was "To Insure Promptitude." Also see here.
tip (v.3)
c. 1200, "to strike, occur suddenly," of uncertain origin, possibly from Low German tippen "to poke, touch lightly," related to Middle Low German tip "end, point," and thus connected to tip (n.); or else related to tap (v.1). Meaning "strike sharply but lightly" is from 1560s. Sports sense is from 1816, originally in cricket. Related: Tipped; tipping.
tip (n.2)
"a light, sharp blow or tap," mid-15c., from tip (v.3).
tip (v.4)
"put a tip on, adorn with a tip," late 14c., from tip (n.) or Old Norse typpa. Related: Tipped; tipping.
实用例句
1. Here's an inside tip: The faster you rise, the harder you fall.
给你一个小忠告：爬得越快，摔得越疼。
来自美剧《绯闻女孩》
2. She poked and shifted things with the tip of her walking stick.
她用手杖尖翻拨挪动东西。
来自柯林斯例句
3. It is usual to tip waiters, porters, guides and drivers.
给服务员、行李搬运工、导游和司机小费是惯例。
来自柯林斯例句
4. We grabbed it just as it was about to tip over.
我们在它就要翻倒时把它抓住了。
来自柯林斯例句
5. Draw the basic outlines in black felt-tip pen (see fig. 4).
