the linear extent in space from one end to the other; the longest dimension of something that is fixed in place
"the length of the table was 5 feet"
the property of being the extent of something from beginning to end
"the editor limited the length of my article to 500 words"
The distance measured along the longest dimension of an object.
"The length of the swimming pool is twenty-five meters, making it perfect for competitive laps."
In plain English: Length is how long something is from one end to the other.
"The length of the hallway was longer than I expected."
Usage: Use length to describe the measurement of an object from end to end, such as the height of a building or the span of a rope. It specifically refers to the greatest dimension when comparing width and depth.
To lengthen.
"The tailor decided to lengthen the hem of my dress because it was too short for dancing."
In plain English: To lengthen something means to make it longer.
"The runner lengthened his stride to catch up with the leader."
Usage: Length is not used as a verb in modern English; you must use "lengthen" or "extend" to describe the action of making something longer. Using "length" as a verb is considered an error and should be avoided.
The word "length" comes from Old English lengþ, which combined the root for "long" with a suffix meaning abstract quality. It entered modern usage directly, retaining its original sense of measurement or extent without significant change in meaning.