What is Default?

Legal Definition
In finance, default is failure to meet the legal obligations (or conditions) of a loan, for example when a home buyer fails to make a mortgage payment, or when a corporation or government fails to pay a bond which has reached maturity. A national or sovereign default is the failure or refusal of a government to repay its national debt. The biggest private default in history is Lehman Brothers with over $600,000,000,000 when it filed for bankruptcy in 2008 and the biggest sovereign default is Greece with $138,000,000,000 in March 2012.
-- Wikipedia
Legal Definition
Borrowers default when they breach a term of their loan agreement. For example, a home owner might go into default by failing to make scheduled mortgage payments.

This entry refers to defaults in a debtor and creditor context. For defaults in a procedural context, see default judgment.

See Debtor and Creditor Law.
Legal Definition
The neglect to perform a legal obligation or duty; but in technical language by default is often understood the non-appearance of the defendant within the time prescribed by law, to defend himself; it also signifies the non-appearance of the plaintiff to prosecute his claim.

2. When the plaintiff makes default, he may be nonsuited; and when the defendant makes default, judgment by default is rendered against him. Com. Dig. Pleader, E 42 Id. B 11. Vide article Judgment by Default, and 7 Vin. Ab. 429; Doct. Pl. 208 Grah. Pr. 631. See, as to what will excuse or save a default, Co. Litt. 259 b.
-- Bouviers Law Dictionary
Legal Definition
Contracts, torts. By the 4th section of the English statute of frauds, 29 Car. H., c. 3, it is enacted that "no action shall be brought to charge the defendant upon any special promise to answer for the debt, default, or miscarriage of another person, unless the agreement," &c., "shall be in writing," &c. By default under this statute is understood the non-performance of duty, though the same be not founded on a contract. 2 B. & A. 516.
-- Bouviers Law Dictionary
Legal Definition
The omission or failure to fulfill a duty, observe a promise, discharge an obligation or perform an agreement State v. Moores, 52 Neb. 770, 73 N. W. 299; Osborn v. Rogers, 49 Hun. 245, 1 N. Y. Supp. 623 ; Mason v. Aldrich, 36 Minn. 283, 30 N. W. 884. In practice. Omission; neglect or failure. When a defendant in an action at law omits to plead within the time allowed him for that purpose, or fails to appear on the trial, he is said to make default, and the judgment entered in the former case is technically called a "judgment by default" 3 BL Comm. 396; 1 Tidd, Pr. 562; Page v. Sutton, 29 Ark. 306.
See also
-- Black's Law Dictionary
Legal Definition
Fault; neglect; omission; failure to appear. See 42 N. J. L. 283.
-- Ballentine's Law Dictionary