also jackknife, large pocket knife, 1711, probably American English, "perh[aps] associated with some sense of JACK sb.1, but compare jackleg knife" [OED]; see jack + knife (n.). Jackleg was a U.S. colloquial term of contempt from c. 1850. On another theory, so called because it originally was associated with sailors. As a kind of swimming dive, from 1922. As a type of tractor-trailer accident, 1966. Both from the notion of folding, as the knife does.
1776, "to stab," from jack-knife (n.). Intransitive meaning "to fold or bend" the body is said to date from the time of the American Civil War. The truck accident verbal sense is from 1949. Related: Jackknifed; jackknifing.
双语例句
1. This guy, Jack Smith, does he go by the name of Jackal?
这个叫杰克·史密斯的家伙是不是还有个名字叫杰凯尔？
来自柯林斯例句
2. Jack had attended these meetings as a matter of routine for years.
数年来，杰克把参加这些会议当成是例行公事。
来自柯林斯例句
3. Auntie Hilda and Uncle Jack couldn't fuss over them enough.
希尔达姨妈和杰克姨父对他们宠爱有加。
来自柯林斯例句
4. Jack took out his notes and talked for just under an hour.
杰克掏出他的笔记，讲了将近一个小时。
来自柯林斯例句
5. An American judge yesterday dismissed murder charges against Dr Jack Kevorkian.
