decimateyoudaoicibaDictYouDict[decimate 词源字典]
decimate: [17] Decimate is a cause célèbre amongst those who apparently believe that words should never change their meanings. The original general signification of its Latin source, the verb decimāre, was the removal or destruction of one tenth (it was derived from Latin decem ‘ten’), and it may perhaps strike the 20th century as odd to have a particular word for such an apparently abstruse operation.

It does, however, arise out of two very specific procedures in the ancient world: the exaction of a tax of one tenth (for which indeed English has the ultimately related word tithe), and the practice in the Roman army of punishing a body of soldiers guilty of some crime such as mutiny by choosing one in ten of them by lot to be put to death. Modern English does not perhaps have much use for a verb with such specialized senses, but the general notion of impassive and indiscriminate slaughter implied in the Roman military use led, apparently as early as the mid- 17th century, to the modern sense ‘kill or destroy most of’.
=> decimal, ten[decimate etymology, decimate origin, 英语词源]
decimate (v.)youdaoicibaDictYouDict
c. 1600, in reference to the practice of punishing mutinous military units by capital execution of one in every 10, by lot; from Latin decimatus, past participle of decimare (see decimation). Killing one in ten, chosen by lots, from a rebellious city or a mutinous army was a common punishment in classical times. The word has been used (incorrectly, to the irritation of pedants) since 1660s for "destroy a large portion of." Related: Decimated; decimating.