A counterpart is something or someone that is equal or similar in value, importance, or function.
When we talk about a counterpart, we usually mean two things that go together, even if they're not identical. For example, in business, you might have a partner who runs the other half of your company - this person would be your counterpart in terms of responsibility and decision-making power. Alternatively, when governments or countries work together on a project, one country might act as a counterpart to another, providing support or expertise in a specific area. In both cases, the idea is that these counterparts are working together towards a common goal, each contributing their own unique strengths and perspectives.
Either of two parts that fit together, or complement one another.
Example: Those brass knobs and their hollow counterparts interlock perfectly
Counterbalance.
