1) n. failure to respond to a summons and complaint served on a party in the time required by law. If a legal answer or other response is not filed, the suing party (plaintiff) can request a default be entered in the record, which terminates the rights of the defaulting party to defend the case. Under a unique New York statute a default can be taken by failure to respond to a summons served without a complaint. 2) the failure to make a payment when due, which can lead to a notice of default and the start of foreclosure proceedings if the debt is secured by a mortgage or deed of trust. 3) v. to fail to file an answer or other response to a summons and complaint, or fail to make a payment when due.