noun / verb
ally
AL-eye/ˈælaɪ/
A partner in mutual support, or to join in such a partnership.
The neighbor becomes an ally in the move, helping lift the heavy couch.

Etymology
The underlying image is being “bound to” someone. The noun first meant a relative or kinsman, then someone united with another by treaty or league—the basis of today's supporting partner.
In context
As an ally, your role is to continuously stand up for others
In 1979, the Soviet Union invaded Afghanistan to back an ally
More examples
- She found an ally in the neighboring town.
- They have allied themselves with a larger coalition.
- Several allies supported the proposal.
Forms
ally · allies · allied · allying
alliance noun — A partnership for mutual support.