partner
US /ˈpɑːrt.nɚ/
UK /ˈpɑːrt.nɚ/

1.
a person who takes part in an undertaking with another or others, especially in a business or company with shared risks and profits
:
•
She became a junior partner in the law firm.
•
They formed a business partnership.
2.
either of a pair of people who are married or in a romantic relationship
:
•
My partner and I are planning a trip to Italy.
•
They have been life partners for over 20 years.
1.
to be the partner of (someone)
:
•
He will partner her in the dance competition.
•
The two companies decided to partner on the new project.