A Prostitute

Friends with benefits, sex with no strings attached

That irritating, not especially romantic state that many married couples fall into when they are no longer young and restless- basically, they're friends with benefits and wedding rings. The purpose of this is to prevent passion from interfering with raising their kids. It's a force of nature, and it is incredibly disturbing to watch as it takes place. There is no known cure except divorce.

An animal that a human keeps as a companion; pet. This phrase is popular among animal rights activists who find the idea of owning a pet to be exploitative.

A more sophisticated and likeable way of saying "fuck buddies". Usually people who are "fuck buddies" aren't really friends. "coitus companions" are when two really close friends fuck on the random occasions that they see each other.

the collaborative, amicable and (ironically) emotionally connecting ending of a relationship done when emotionally mature, emotionally healthy people respectfully acknowledge their differing wants and needs and agree together within a context of mutual respect to end the aspects of their relationship which do not serve them, sometimes enabling them to part as friends with love in their hearts.

The person you spend time with on a particular evening.