Damaging the reputation of a person or a group of people by publishing or saying bad things about them that are not true. More specifically, saying words which amount to defamation is slander and defamation in other forms, such as printed words or images, is libel.

A formal promise by one party (the guarantor or surety) to another party (the creditor) to accept responsibility of a third party’s (the principal debtor) debt, if that third party cannot or refuses to pay it.