When you write either an extended or a brief definition, you can use any of the following tactics to support your version of a word’s meaning.

Synonym: Provide a roughly equivalent word or phrase (e.g. "altruism or self-sacrifice").

Genus/Difference: Name the genus or category the concept belongs in, selecting a category your audience will recognize (e.g. "A mongoose is a small mammal!"). Then choose the striking characteristics that make your term different from others in that Category. (e.g. "A mongoose attacks and eats venomous snakes."). This distinguishing can use any mode of development in this entire list, depending on the word.

Analysis: If you want to make your readers aware of important distinctions or partitions under a single term, divide the concept into parts, each with an appropriate label. (e.g. there are two forms of DNA coiling, right-handed and left-handed.)

Classification: If your term represents a category with many members, you can classify or sort out those diverse members into subcategories as an early step in definition. (e.g. "there are three types of progressive rock: gothic, industrial and technorave") (in writing, analysis and classification produce a similar portioning of the whole. The author switches to defining the parts which can then be compared with each another, etc.)

Process: If your term stands for a method or procedure, tell how it is done. You might even detail the steps chronologically. (e.g."Decoupage is the technique of decorating a surface with cutouts")

Description: If the term you are defining stands for something tangible, select the details (sounds, sights, smells, etc.) that make if recognizable. (e.g. "An Erlenmeyer flask is shaped like a cone with a broad base and a narrow neck.").  (Examples): Select members/specific instances of the group represented by your term. These examples can also be expanded by other modes like description or comparison. (e.g. "An idiom is an expression that cannot be understood from the meanings of the individual works, like ‘hail mary’ and ‘throw in the towel.’")

Etymology: Take the word itself apart to show how it was formed from its roots or combined from other words of borrowed completely from another language. (e.g. "The word lederhosen comes from two German word, leder meaning leather and hosen meaning pants.")

Genealogy/History: Trace the origin of the concept and its development over time. If your purpose is to cover the many meanings of a single word, this method invites you to show branching or shifting meanings over time. (e.g. "The word bureau which now means an office or agency or a dresser or chest of drawers, once referred to the woolen cloth that was sometimes used to cover a desk. Imagine the ‘Federal Woolen Cloth of Investigation’")

Negation: Tell what the meaning does not include. Instead of giving examples, give exceptions, or list features not included, etc. You may even create extremes in different "directions" which mark the boundaries around but not part of your concept. (e.g. "Communitanianism is neither a form of liberalism nor a form of conservatism.")

Contrast with close terms: Use this tactic if your word is frequently confused with other terms that seem to have the same meaning. Trace the subtle differences between your word and the other or others that might be mistaken for synonyms. (e.g. "Frugality is not quite the same as parsimony, thought the two are sometimes confused.")

Comparison: Choose analogies with concepts, things, processes, etc., that are more familiar to your audience. These comparisons can be partial. Your term can be like one thing in one respect, like another in another. (e.g." A pilchard is like a herring.")

Metaphor: Select a surprising category that your term does not actually belong in but which yet epitomizes or clarifies it. Though all tactics of definition suggest values, this tactic is often used to express an attitude or judgment like contempt or admiration. (e.g. "Top 40 music is bubblegum for the ears.")

Operation: Describe a test or action or rule of thumb by which something qualifies as part of your concept. If something passes this test or results from this action, it gets called by your term. (e.g. "Everything in this garden plot does not have a dark green, serrated leaf is a weed.")

Circumstances of Use or Social Context: Describe the kind of situation or circumstances, or perhaps even the social setting, in which it would be appropriate to use your word. Or, by contrast, describe some of the circumstances in which it would not be appropriate to use it. You can describe hypothetical situations, appropriate or inappropriate, or you can cite actual instances of the word’s use. (e.g. "Striking union members call anyone who works for the company they are boycotting a scab, or "In legal proceedings and courts, the person who brings a suit against another is called the plaintiff.")