Partner

A partner was anyone who entered into a partnership with another person, whether being a business partnership such as a sidekick; or a domestic partnership, such as marriage mates or sexual partners. 

In 2256, when Paul Stamets was behaving strangely due to his experience with the spore drive, Doctor Hugh Culber told and Burnham to excuse his partner, as he hadn't been himself lately. 

In 2266, Benton and Gossett where the business partners of Ben Childress. They worked as lonely miners on Rigel XII and were the victims of Harry Mudd's con job. 

When he heard that Wesley Crusher couldn't dance, Data offered to give him dance lessons. He had created a comprehensive seventeen-part course with some "interesting holographic dancing partners". 

When Quark was chosen to conduct negotiations for acquisition of tulaberry wine with the Dosi in 2370, it was suggested that he may need someone to work with him to take the blame of a potential failure. At first Rom suggested that he be chosen as a consultant help him, however, Quark instead chose Pel, not as a partner, but as an assistant, at the agreed rate of 20 percent of the profits.