The noun length has 5 senses (first 4 from tagged texts)
1. (56) length -- (the linear extent in space from one end to the other; the longest horizontal dimension of something that is fixed in place; "the length of the table was 5 feet")
2. (7) duration, length -- (continuance in time; "the ceremony was of short duration"; "he complained about the length of time required")
3. (3) length -- (the property of being the extent of something from beginning to end; "the editor limited the length of my article to 500 words")
4. (1) distance, length -- (size of the gap between two places; "the distance from New York to Chicago"; "he determined the length of the shortest line segment joining the two points")
5. length -- (a section of something that is long and narrow; "a length of timber"; "a length of tubing")