Your partner is the person you are married to or are having a romantic or sexual relationship with.

Your partner is the person you are doing something with, for example dancing with or playing with in a game against two other people.

The partners in a firm or business are the people who share the ownership of it.

The partner of a country or organization is another country or organization with which they work or do business.

If you partner someone, you are their partner in a game or in a dance.