Thousandth

noun

1. The ordinal number matching the number 1,000 in a series.
2. One of 1,000 equal parts.
3. Last in order of a series of a thousand; next after the nine hundred and ninety-ninth: an ordinal numeral.
4. Constituting one of a thousand equal parts into which anything is divided.
5. One of a thousand equal parts into which anything is divided.