A counterpart is a person or thing that has the same role, function, or position as another person or thing, but in a different place, group, or situation. If your school's debate team competes against another school, their captain is your team captain's counterpart: both lead their teams and have the same responsibilities, just for different schools.

The word helps us compare similar roles across different contexts. The Secretary of State might meet with her counterpart from France, meaning the French official who handles the same kinds of international relationships. In a business merger, the sales director from one company would work closely with her counterpart from the other company, since they both understand sales from their respective sides.

You might also use counterpart when comparing things. In biology class, you might learn that a bird's wings are the counterpart of a bat's wings: different creatures with similar structures serving the same purpose. A violin section in an orchestra could be called the counterpart of the first row of singers in a choir, since both carry the melody.

The word suggests a kind of mirror image: not identical, but parallel. When you find someone's counterpart, you've found their equivalent on the other side of some divide.