Fortieth (adjective)

The ordinal number that is the product of 10 and 4, being one of the forty numbers of the same name in a sequence.

Origin:

Derived from the word 'forty'.

Examples:

1. He was just turning fortieth, and still felt young at heart.
2. The fortieth president of the United States was Ronald Reagan.
3. This was the fortieth year of their marriage.
4. The fortieth parallel north is a circle of latitude that is 40 degrees north of the Earth's equatorial plane.
5. The fortieth anniversary of the company was celebrated with a big party.