length 
/ˈlɛŋθ/ noun
plural lengths /ˈlɛŋθ/ noun 1 a : the distance from one end of something to the other end : a measurement of how long something is [noncount] ▪ “What is its length?” [=how long is it?] “It measures 10 inches in length.” [=it is 10 inches long] ▪ We walked the entire length of the beach. [=we walked from one end of the beach to the other] ▪ The length of the table is six feet, and its width is three feet. [count] ▪ These pins are available in one- and two-inch lengths. ▪ The adult animals reach a maximum length of two meters. — see also focal length
b [noncount] : the size or extent of a piece of writing
▪ Your essay should be no more than 250 words in length. ▪ five pages in length [=five pages long] ▪ a book-length poem [=a very long poem; a poem that has the same number of pages as some books]
c [noncount] : the quality or state of being long
▪ Don't be put off by the book's length. [=(less commonly) lengthiness] ▪ I was amazed by the length of the ape's arms. [=by how long the ape's arms were] 2 [noncount] : the amount of time something lasts
▪ They want to extend the length of the school year. [=to make the school year longer; to lengthen the school year] ▪ the length of a movie ▪ If you're in town for any length of time [=for more than just a short time], be sure to see the museum. 3 [count] : the length of something used as a unit of measure
▪ Our horse won the race by a length. [=by a distance equal to the length of one horse] ▪ They were two car lengths behind us. ▪ I managed to swim four lengths of the pool. [=to swim from one end of the pool to the other end four times] — see also at arm's length at 1arm 4 [count] : a piece of something that is long and thin or narrow
▪ a length of pipe/chain/yarn 5 [noncount] : a measure of how far down on your body something (such as your hair or a piece of clothing) reaches
▪ the length of a skirt ▪ a waist-length jacket [=a jacket that reaches only to your waist] ▪ chin-length hair — see also floor-length, knee-length, shoulder-length
b [noncount] : the size or extent of a piece of writing
▪ Your essay should be no more than 250 words in length. ▪ five pages in length [=five pages long] ▪ a book-length poem [=a very long poem; a poem that has the same number of pages as some books]
c [noncount] : the quality or state of being long
▪ Don't be put off by the book's length. [=(less commonly) lengthiness] ▪ I was amazed by the length of the ape's arms. [=by how long the ape's arms were]
▪ They want to extend the length of the school year. [=to make the school year longer; to lengthen the school year] ▪ the length of a movie ▪ If you're in town for any length of time [=for more than just a short time], be sure to see the museum.
▪ Our horse won the race by a length. [=by a distance equal to the length of one horse] ▪ They were two car lengths behind us. ▪ I managed to swim four lengths of the pool. [=to swim from one end of the pool to the other end four times] — see also at arm's length at 1arm
▪ a length of pipe/chain/yarn
▪ the length of a skirt ▪ a waist-length jacket [=a jacket that reaches only to your waist] ▪ chin-length hair — see also floor-length, knee-length, shoulder-length
at length 1 : for a long time
▪ We talked at length about the ceremony. ▪ The speaker went on at considerable/great/some length. ▪ No one was questioned at any length about it. [=no one was questioned for a long period of time] 2 : in a full or complete way
▪ The topic will be treated at length in the next chapter. ▪ The book doesn't discuss the topic at any length. [=the book only discusses the topic briefly] 3 literary : after a long time
▪ At length [=finally, in the end, at last], we decided to return home.
▪ We talked at length about the ceremony. ▪ The speaker went on at considerable/great/some length. ▪ No one was questioned at any length about it. [=no one was questioned for a long period of time]
▪ The topic will be treated at length in the next chapter. ▪ The book doesn't discuss the topic at any length. [=the book only discusses the topic briefly]
▪ At length [=finally, in the end, at last], we decided to return home.
go to any length or go to any/extreme/great (etc.) lengths
: to make a great or extreme effort to do something
▪ She'll go to any length to avoid doing work. = She'll go to any lengths to avoid doing work. ▪ He went to great lengths to learn the truth.
▪ She'll go to any length to avoid doing work. = She'll go to any lengths to avoid doing work. ▪ He went to great lengths to learn the truth.
the length and breadth of
: through all parts of (a place)
▪ I've been/traveled the length and breadth of the canyon, but I still haven't found the caves I'm looking for.
▪ I've been/traveled the length and breadth of the canyon, but I still haven't found the caves I'm looking for.
