Thousandth
A thousandth is one of a thousand equal parts of something. It is 1000th written as a word.
10−3 ; 0.001; 1000−1; one thousandth
One part in a thousand equal parts: 1/1000th
Example:
1 meter is a thousandth of 1 kilometer
1m = 1/1000 km = 0,001km