Circular definition

There are several kinds of circular definition, and several ways of characterising the term: pragmatic, lexicographic and linguistic.

The classic "genus-difference" dictionary definition is in terms of nearest kind (genus proximum) and specific differences (differentia specifica).

Dictionary production, as a project in lexicography, should not be confused with a mathematical or logical activity, where giving a definition for a word is similar to providing an explanans for an explanandum in a context where practitioners are expected to use a deductive system.

[6][7] While, from a linguistic prescriptivist perspective, any dictionary might be believed to dictate correct usage, the linguistic descriptivist perspective recognizes that looking up words in dictionaries is not itself a rule-following practice independent of the give-and-take of using words in context.

[citation needed] While a dictionary might produce a "circle" among the terms, "oak", "catkin", and "acorn", each of these is used in different contexts[clarification needed] (e.g., those related to plants, trees, flowers, and seeds) that generate ever-branching networks of usages.

[citation needed] The 2007 Merriam-Webster dictionary defines a "hill" and a "mountain" this way: Merriam-Webster's online dictionary provides another example of a circular definition with the words "condescending" and "patronizing:" From "condescension": To "patronize": From the Oxford Dictionary of English: Therefore, a punishment means "a punishment imposed for breaking a law, rule, or contract inflicted as punishment inflicted on someone as punishment inflicted or retribution exacted for an injury or wrong for a wrong or criminal act for an offence".

Formal approaches to characterizing circular definitions are found in logic, mathematics and in computer science.

Circular sets are good for modelling cycles, and, despite the field's name, this area of mathematics is well founded.