The phrase "combo breakers" refers to actions or events that interrupt or stop a sequence of successful actions. It's often used to describe situations where someone puts an end to a winning streak or a series of accomplishments. Full definition
For example, if you know your opponents combo string will use a light attack next, pushing light kick with light punch will cause combo breaker. (gamingunion.net)
Otherwise, the practice mode operates as expected, and there's a very useful combo breaker training mode which helps when learning to break specific characters. (ticgn.com)
Then unleash a massive combo breaker attack on him after the heal. (zeboyd.com)