There are several defamation terms, including slander and liable. However, in some cases, there is no need to determine whether an incident involved slander or liable specifically and instead, the courts refer to defamation terms.
A defamation term may come into play during a civil trial. For example, a defamation term may have been used to bring a civil cases against an individual or entity in cases where an individuals reputation was harmed by another individual or entity.
Defamation of charterer for example, can include more specif charges. It may for example, be alleged that an individual distributed materials that were harmful to the reputation of another individual or entity. Those materials may be included under specific terms such as slander or liable, or the more broad defamation term.
Civil laws has more information about defamation.