A person who shares or is associated with another in some action or endeavor.

A person who is in a romantic relationship with another.

प्रेमी/प्रेमिका

English Usage: He is her partner in life.

Hindi Usage: वह उसके जीवन का साथी है।

To join or associate with someone.

सहयोग करना

English Usage: They decided to partner with another firm for the project.

Hindi Usage: उन्होंने परियोजना के लिए किसी और फर्म के साथ सहयोग करने का निर्णय लिया।