A definition is a brief and precise description of a thing by its properties; an explanation of the signification of a word or term, or of what a word is understood to express. Logicians distinguish definitions into nominal and real. A nominal definition explains the meaning of a term by some equivalent word or expression supposed to be better known. A real definition explains the nature of the thing. A real definition is again accidental, or a description of the accidents, as causes, properties, effects, etc; or essential, which explains the constituent parts of the essence or nature of the thing. An essential definition is, moreover, metaphysical or logical, defining 'by the genus and difference', as it is called; as, for example, 'a plant is an organized being, destitute of sensation', where the part first of the definition states the genus (organized being), and the latter the difference (destitute of sensation, other organisms/beings possessing sensation); or physical, when it distinguishes the physical parts of the essence; thus, a plant is distinguished by the leaves, stalk, root, etc. A strictly accurate definition can be given of only a few objects. The most simple things are the least capable of definition, from the difficulty of finding terms more simple and intelligible than the one to be defined. Research Definition
Abbreviations
General Information
Research Definition