defeat of reasons See EPISTEMOLOGY, JUSTIFICA -. TIO. definiendum (plural: definienda), the expression that is defined in a definition. The expression that gives the definition is the definiens (plural: definientia). In the definition father, male parent, ‘father’ is the definiendum and ‘male parent’ is the definiens. In the definition ‘A human being is a rational animal’, ‘human being’ is the definiendum and ‘rational animal’ is the definiens. Similar terms are used in the case of conceptual analyses, whether they are meant to provide synonyms or not; ‘definiendum’ for ‘analysandum’ and ‘definiens’ for ‘analysans’. In ‘x knows that p if and only if it is true that p, x believes that p, and x’s belief that p is properly justified’, ‘x knows that p’ is the analysandum and ‘it is true that p, x believes that p, and x’s belief that p is properly justified’ is the analysans. See also ANALYSIS, DEF- INITION , MEANIN. T.Y.