length/lengthy

length /leŋθ/ n.［u］1. 长；长度：a room 5 metres in length and 3 in breadth 长5米宽3米的房间 2. 用于习语 at length 1.详细地，全面地：These aspects have been discussed at length. 这些方面都已详细讨论过了。2. 很长时间之后：At length she laid down the pencil. 很长时间之后，她放下铅笔。at full length 全身平伸地：lie at full length on the grass 伸直身体躺在草地上 go to great lengths竭尽全力干成某事：I went to great lengths to explain the situation to him but he still didn’t seem to understand. 我竭尽全力把情况向他解释，但看样子他仍然不理解。

 lengthy /leŋθi/ adj. 长的，漫长的：The professor wrote a lengthy book on Napoleon.教授写了一部有关拿破仑的巨著。Agreement was finally reached after very lengthy discussions.经过漫长的讨论之后协议终于达成。