ally
Definitions
A state or person formally cooperating with another for a military or other purpose.
A person or organization that cooperates with or helps another in a particular activity.
To combine or unite a resource or commodity with another for mutual benefit.
Examples
The two countries decided to become a strategic ally in the region.
She has been a loyal ally to me throughout my entire career.
It is important to find an ally who shares your vision for the project.
Synonyms
partner associate colleague confederate accomplice supporter friend