Which term describes a significant violation of a contract or obligation?

The term that describes a significant violation of a contract or obligation is a serious breach. A serious breach occurs when one party fails to perform their contractual obligations in a substantial way, which typically deprives the other party of the benefits they were supposed to receive under the contract. This type of breach can often lead to legal consequences, allowing the non-breaching party to terminate the contract and seek damages.

In contrast, other concepts like a minor breach denote a situation where the violation is not serious enough to warrant termination of the contract, and the non-breaching party can still recover damages. Normal breach and occasional breach are not established legal terms that effectively categorize the severity of breaches. Thus, recognizing a serious breach is crucial for parties to understand their rights and the gravity of the situation when a contract is violated.