Adversarial means acting like an opponent or enemy, treating someone as if you're working against them rather than with them. When two lawyers take an adversarial approach in court, they challenge each other's arguments forcefully, each trying to win for their side. The American legal system is built on this adversarial model: prosecutors and defense attorneys face off, presenting opposing cases while a judge or jury decides the outcome.

In an adversarial relationship, the two sides see each other as competitors rather than collaborators. During a debate, students might take adversarial positions on whether homework should be banned, each side attacking the other's arguments. This is different from a discussion where people work together to find common ground.

Not everything needs to be adversarial. When your teacher corrects your math homework, that's not adversarial because you're both working toward the same goal: helping you learn. But when two chess players face each other across the board, their relationship is adversarial: each wants to defeat the other.

People sometimes become unnecessarily adversarial, turning every conversation into a contest.