noun
length
LENGKTH/leŋkθ/
The extent measured between a beginning and an end.
The strip's length spans ten units on the ruler beneath it.

Etymology
The suffix turns “long” into a noun for the property of extending in one direction. Length names that measurable extent, whether the object itself is long or short.
In context
we use those units to talk about the distance between two points in a straight line okay so that's the unit and the concept of length
More examples
- The length of the movie surprises us.
- The ropes come in several different lengths.
- The length of the article depends on the topic.
Forms
length · lengths
lengthen verb — To make or become longer.
lengthy adjective — Taking considerable time or written space.