What term refers to the measurement of how long a needle is?

The term that refers to the measurement of how long a needle is is "length." In medical terminology and practices, length specifically describes how long an object is from one end to the other. When discussing needles, the length is crucial, as it can affect the depth of penetration and the type of procedures for which a needle can be used.

In contrast, diameter refers to the thickness or width of the needle, height typically pertains to vertical measurements, and width may describe the breadth of an object, none of which accurately describe the measurement of how long a needle is. Length is the appropriate term for this specific dimension.