length/ lεŋθ /

1.noun [of object] [ animal] 
(size) 长度

2.noun [of sentence] [ article] 
篇幅

3.noun [of wood] [ string] [ cloth etc] 
(piece) 一段

4.noun [c] 
(in swimming pool) 长度

5.noun [c/u] 
(duration) 期间

at length
详尽地
6.noun [liter] 
(at last) 最后

it is 10 metres in length
10米长
to go to great lengths to do sth
竭尽全力做某事
they travelled the length of the island
他们走遍了整个岛屿