partner Definition

partner
noun

1. One of two or more people who jointly own or run a business or other enterprise on an equal footing.

Thesaurus: associate, colleague, accomplice, helper, collaborator, ally.
2. A person with whom one has a sexual relationship, especially a long-term one, particularly in a committed unmarried or same-sex relationship.
3. A person one dances with.

Example: dance partner
4. A person who is on the same side as oneself in a game of eg bridge, tennis, etc.
5. biol.
An associate in commensalism or symbiosis.

verb

partnered, partnering
1. To join as a partner with someone; to be the partner of someone.

Etymology: 13c as partener: from parcener joint inheritor, influenced by part.