Origin: Greek prefix micro-
Micrometer has 4 different meanings across 1 category:
a metric unit of length equal to one millionth of a meter
caliper for measuring small distances
An SI/MKS unit of measure, the length of one millionth of a meter. Symbols: µm, um, rm.
A device used to measure distance very precisely but within a limited range, especially depth, thickness, and diameter.