1. Slang Extortion of money, as by blackmail.
2. Slang A thorough search of a place or person.
3. A period of appraisal followed by adjustments to improve efficiency or functioning.
4. Serving to test the performance of a ship or an aircraft and to familiarize the crew with operation of the craft:
a shakedown cruise; a shakedown flight.
5. In 1969 a majority of the members of the American Heritage Dictionary Usage Panel felt that the noun shakedown in the sense “extortion” and the related phrasal verb shake down were acceptable in writing, though both are now labeled slang. It would seem that certain usages take a while to attain respectability because of the company they keep. Shake and the verb phrase shake out of already meant “to steal” in Middle English. This usage of shake is still found in the 19th and 20th centuries. Both shake and shake out of in the sense “to steal” are clearly related to shake down, which is first recorded in 1872, shake down being glossed “to extort money from individuals.” This is a slang usage, probably occurring, as had the verb shake, largely in contexts having to do with criminal or corrupt behavior. As our Panel realized, the verb and the later noun shakedown (first recorded in 1902 in the United States) have now moved from the lingo of criminals, loan sharks, and politicians into wider currency.
1969年，大多数美国经典辞书 用法研究小组的成员认为名词 shakedown （意为“敲诈”）及相关的短语动词 shake down 在写作中是可接受的， 虽然现在两者均被标以俚语。 与之有关的意义似乎有些用法需要一些时间来获得社会的承认。在中世纪英语中，Shake 和 shake out of 已经意味着“偷盗” 。 shake 的这种用法仍见于19世纪和20世纪。 Shake 及 shake out of （意为“偷盗”）明显与 shake down （首次记载于1872年）有所联系。 shake down 被解释为“从个人处敲诈金钱”。 这是俚语用法，很可能如动词shake 一样，大量用于与犯罪或腐败行为有关的语境中。 正如我们的用法研究小组所意识到的，该动词及后来的名词shakedown （在美国最早记载于1902年）已从罪犯、高利贷者及政客的语汇发展到更广泛的使用领域