1887 in figurative sense of "useless person or thing," originally American English, from dead (adj.) + wood (n.). Dead wood in a forest is useful as firewood; perhaps the reference here is to the dried up parts of plants grown for commercial production of flowers or fruit.
权威例句
1. At last I had the deadwood on the Red Pony.
最后我终于制服了那匹红马驹.
2. The Methods: Used have helped enormously in cutting out deadwood.
这些方法在废物利用方面起了相当大的作用.
3. The remainder are standing deadwood, still valuable to the forest because of the life they support.
其余下的是直立的朽木, 对森林来说仍然很重要,是因为它们能维持其它树木的生命.
4. What a shock! I thought you might have been killed by Captain Deadwood.
真的吓了跳. 我还以为你已经被朽木队长杀死了.
5. They have the deadwood on you now, for they know you took that girl into your room.