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The Writer’s Reference Book


Module G – Definition – Hint Sheet

A definition identifies the essential qualities and limits the meaning of a term. A definition answers the question “What is it?” A definition defines a term (bottle) – not a thing (baby bottle).

Use definition when:

  • You use a term your audience may not know (e.g., prototype).
  • When a term has several possible meanings (e.g., courage).
  • When a term may be too vague without further explanation (e.g., liberal).
  • When you want your audience to know that you're using a term which holds a particular technical or professional meaning (e.g., Victorian Literature).

Different defining methods

  • Definition by word substitution offers a word or phrase that could be used in place of the unknown term. do not use the term in its definition; this results in a circular definition.
    • Yes: Democracy is “a government in which the supreme power is vested in the people.”
    • No: Democracy is a democratic form of government.
  • Definition by synonym equates the term to be defined with a term that has about the same meaning. do not use a synonym that your audience will not be familiar with.
    • Yes: A lanai, or porch, ran the length of the house. (Nearly everyone knows what a porch is.)
    • No: A prototype is an archetype. (Few people know what an archetype is.)
  • Definition by negation – telling what something is not – is not helpful unless it is combined with a positive definition.
    • Yes: To praise is not to applaud, celebrate, commend, flatter, or puff – but rather it is to nurture the human spirit.
    • No: A horse is not an alligator.
  • You can define by citing an example: Democracy is the type of government that can be found in the U.S.A., Great Britain and Canada.
  • Rhetorical definitions are personal and subjective, and they require development. They ask for explanation.
    • Example: “Time is but the stream I go fishing in.” (Henry Thoreau)
  • Definition by function explains what something does or how something works.
    Definition by structure tells how something is organized or put together.
    • By Function: A plumb bob offers a perfect reference for vertical alignment when suspended from above because its weight hangs straight down.
    • By Structure: A plumb bob is a pointed weight at the end of a string.
  • An analytical definition places the term in a class and then explains how that term differs from other terms in the same class. A gibbon, for example, is in the same class of apes as an orangutan, but it differs in size and geographic location.

Related Terms

Definiendum: the term being defined. Definiens: the terms used for defining. Definiens have two parts: (1) genus, the general class or first level of classification and (2) differentia, the special characteristics of the genus.

Example: A vegetarian is a person who eats no meat.
Definiendum: vegetarian. definiens: person who eats no meat;
genus: person; differentia: eats no meat

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