How do you define ordinal number?

An ordinal number is defined as a number that identifies a position in a sequence or system of levels or rankings.

You can write ordinal numbers as words (e.g., “third”) or cardinal numbers combined with “-st,” “-nd,” “-rd,” or “-th” (e.g., “20th”).

For example, someone might live on the 31st floor of a building or win fourth place in a competition.

When you’re writing with ordinal numbers, QuillBot’s free Grammar Checker can help you avoid errors.