Thou″sandth (?), a. 1. Next in order after nine hundred and ninty-nine; coming last of a thousand successive individuals or units; — the ordinal of thousand; as, the thousandth part of a thing.
2. Constituting, or being one of, a thousand equal parts into which anything is divided; the tenth of a hundredth.
3. Occurring as being one of, or the last one of, a very great number; very small; minute; — used hyperbolically; as, to do a thing for the thousandth time.