Millionth,

Definition of Millionth:

1. Constituting number one million in a sequence; 1,000,000th.

2. Each of one million equal parts into which something is or may be divided.

3. One part in a million. Equivalent to 1/1,000,000.

How to use Millionth in a sentence?

1. A dot less than a millionth of an inch in diameter.
2. The museum welcomed its millionth visitor 21 months after opening.