How to Write an Extended Definition

Usually when you hear the word "definition" you think of a dictionary or encyclopedia. For example: a juvenile delinquent is: an underage person convicted of crime or antisocial behavior. Likewise, a venture capitalist is: a person who provides money for innovative projects.
Perhaps you have writen a narrative essay about a personal experience. In the social sciences, you are often called upon to classify and to analyze causes and effects. All of these patterns and more can be used in your paragraphs to clarify and extend the term you have chosen.

Example: Single Pattern
Sometimes a single pattern will be sufficient to extend the definition to achieve the effect you want for your audience. For example, let's say in an introductory sociology course, you are introducing the term "juvenile delinquent" to the class. You could use the "classify" pattern to clarify how broadly the term in used in this field:

Term: juvenile delinquent
Standard definition: an underage person who has committed a crime.
Pattern: Classify
Overall Point: To understand "juvenile delinquent" in this field, it's necessary to know the major types of delinquents.
Support points:
     The first type of delinquent is . . .
     The second type 
of delinquent is . . .
     The third type
of delinquent is . . .

Example: Multi Pattern
Depending on the term, you may find that using several patterns is the best way to help shape your audience's understanding of a term. For example, let's consider the innocent sounding term "arbitration." Maybe you wish to make the point that sometimes legal terms are used to desensitize us from what is really taking place. Consider this example:

Term: Arbitration
Standard definition: legal process of resolving a dispute
Classify Pattern--list and define types of arbitration, including "forced arbitration"
Narration Pattern--Jamie Leigh Jones, brutally raped by Halliburton coworkers in Iraq, was required to submit to forced arbitration without appeal.
Cause/Effect pattern: Deprived of due process of law, Jamie's rapists went free

In the End
Your task in writing an extended definition is to add to the standard/notional definition in a way that will allow your audience to gain a deeper and more nuanced understanding of the term in a particular context. Whether you do this by adding facts, telling what a term does not include, or applying any of the many development patterns (classify, illustrate, cause/effect, compare/contrast, narration, description), matters not. Only the development of clear understanding between you and your audience should be the ultimate goal.