Which prefix represents one thousandth?

The prefix that represents one thousandth is "milli," denoted by the symbol "m." In the metric system, "milli" indicates a factor of one thousandth (1/1000 or 0.001). For example, a millimeter is one thousandth of a meter, and a milligram is one thousandth of a gram. This prefix is widely used in various fields, including science and engineering, to describe measurements that are smaller than the base unit but still significant for precise applications.

In contrast, the other prefixes serve different purposes: "kilo" means one thousand, "micro" represents one millionth (1/1,000,000 or 0.000001), and "nano" indicates one billionth (1/1,000,000,000 or 0.000000001). Understanding these prefixes is crucial for converting and interpreting measurements within the metric system effectively.