partner

noun
  1. A person who shares or is associated with another in some action or endeavor; a participant. noun
    She is my partner in the dance competition.
    They are business partners in the new startup.
  2. Either of two people who dance together. noun
    He asked her to be his partner for the waltz.
    The dance instructor paired the students with partners.
  3. A person with whom one shares an intimate relationship; a spouse or lover. noun
    He introduced his partner at the family gathering.
    They have been partners for over ten years.
  4. A member of a partnership, especially in a business. noun
    She became a partner at the law firm last year.
    The partners agreed on the new business strategy.
  5. To join or associate with another as a partner. verb
    The company decided to partner with a local charity.
    They partnered with another team to complete the project.