What term describes a party that fails to perform according to the terms of a contract?

The term "in default" accurately describes a party that fails to perform according to the terms of a contract. When one party does not fulfill their contractual obligations—whether that means not delivering services, failing to make payments, or not adhering to any other specified terms—they are considered to be in default. This legal classification carries specific implications, including the right of the other party to pursue remedies for breach of contract, which may include seeking damages, specific performance, or contract termination.

The other terms do not correctly capture the situation of failure to perform under a contract. "In avoidance" refers to a party's efforts to cancel or avoid the contract obligations altogether, while "terminated" indicates that the contract has been ended, which may not necessarily reflect the failure to perform by one of the parties. "In violation" might suggest breach of law or regulation but does not specifically denote failure to perform under the terms of a contract. Therefore, "in default" is the precise term for a party that does not adhere to their contractual obligations.