Why circular definitions are avoided in technical writing

How to Define Terms That Don’t Make Readers Scratch Their Heads

If you write anything technical—user guides, manuals, API docs, or help articles—definitions aren’t a bonus feature. They’re a core part of clarity. Readers don’t want to guess what a term means while they’re focused on a task. They want a clean, quick explanation that fits right into the sentence they’re reading. In the world of technical communication, there are several solid ways to structure definitions. One route, however, is a don’t: circular definitions. Let me explain why and how the other approaches work better.

The one to avoid: circular definitions

Think of a circular definition as a loop with no exit sign. A term is defined by using the term or a close variant of it. For example: “A glossary entry is a glossary entry.” It’s tautological—saying nothing new. The moment you see a sentence like that, you and your reader both sense the snag: you’re not adding any meaning, just circling back to where you started.

Why is this a problem? Because readers rely on definitions to gain clarity, not to chase their tails. If the goal is understanding, a circular definition delivers confusion, not knowledge. It can slow someone down exactly where speed matters—during setup, troubleshooting, or when a reader is scanning for answers.

The other routes that actually help

Now, let’s tour the three constructive ways to structure definitions. Each has its own flavor and best-use scenario. The key is to choose the form that fits your document’s rhythm and your audience’s needs.

1. Sentence definitions: one clear sentence, no fluff

What they are: A concise, standalone sentence that states what the term means.

Why they work: They deliver a quick, complete description. They’re ideal for glossaries, quick-reference boxes, or places where you want a term defined without pulling the reader away from the page.

A solid example:

• Latency: the time between sending a request and receiving a response.

A few quick notes:

• Keep it precise. If you can replace the term with “it” and the sentence still makes sense, you’ve probably written a good sentence definition.

• Avoid circular phrasing. Don’t reuse the term in the definition.

• If a term still needs context, that context can live in a separate sentence nearby, but the core definition should stand alone.

2. Expanded definitions: context, examples, and contrasts

What they are: A broader definition that adds context, examples, non-examples, and sometimes brief contrasts to solidify meaning.

Why they work: Some terms are tricky or domain-specific. A well-crafted expanded definition gives readers a richer mental model. It moves beyond “what it is” to “how it behaves in the real world.”

A clear example in a software context:

• Idempotent (operation): An operation that can be repeated with the same result as a single execution. For instance, setting a user’s status to "active" is idempotent because repeating the action yields the same final state. In contrast, incrementing a counter is not idempotent, since repeated executions increase the value each time.

A few tips when you use expanded definitions:

• Start with the core idea, then layer on examples.

• Include a brief contrast or a non-example to prevent ambiguity.

• Tie the definition to how readers will encounter the term in the product or process.

3. Parenthetical definitions: define in the flow, without breaking momentum

What they are: A definition tucked into a sentence using parentheses or dashes, so the reader gets the meaning right where it’s needed, without stopping the flow.

Why they work: They’re especially handy in procedural writing or in documentation that’s meant to be read linearly. The reader gets the sense of a continuous narrative while still getting a precise definition on the spot.

A practical example:

• When you call this function, the operation is non-destructive (it does not alter the input data).

A note on balance:

• Use sparingly. If you overload a sentence with a parenthetical definition, the sentence can feel bloated. The goal is to smooth the read, not derail it.

Putting it all together: when to choose which approach

• Glossaries and quick guides: sentence definitions shine. They’re fast, readable, and easy to scan.

• Technical procedures and API docs: expanded definitions help users understand edge cases, performance implications, or how a term behaves in different contexts.

• Inline explanations within prose: parenthetical definitions can be a natural fit, especially when a term appears only once or twice and you don’t want to break the narrative.

A tiny example set, all about the same term

Let’s pretend we’re documenting a simple data operation called “trim”:

• Sentence definition: Trim removes whitespace from the beginning and end of a string.

• Expanded definition: Trim removes whitespace from the beginning and end of a string, producing a new string without leading or trailing spaces. This is useful when parsing user input where accidental spaces can cause errors; note that internal spaces are not affected.

• Parenthetical definition: Trim (remove leading and trailing whitespace) is applied before validation.

Notice how the same term can be defined in different flavors depending on where it appears in your document. Readers get just enough to move forward, without getting bogged down.

Practical tips that make definitions more useful

• Define once, then reuse: If a term appears in multiple places, a single, well-crafted definition in a glossary or a definitions section anchors meaning. In nearby text, you can rely on that established meaning without redefining it every time.

• Keep definitions current: As products evolve, terms can shift in meaning. A quick review of your definitions during a content refresh helps maintain accuracy.

• Tie definitions to behavior: In technical docs, readers care about what a term does, not just what it is. Whenever possible, include how the term behaves in typical scenarios.

• Use plain language first: Technical terms should be defined in accessible language. If you can explain it in a sentence that a non-specialist could understand, you’re probably on the right track.

• Include examples and non-examples: A concrete example often clears up ambiguity. A non-example helps readers see what the term does not mean, too.

• Pair with visuals when helpful: A small diagram or a snippet can reinforce a definition, especially for terms tied to processes or data structures.

Common pitfalls to avoid

• Circular definitions: They’re the most obvious trap. If your definition leads readers back to the term without adding new information, you’ve missed the mark.

• Overloading with jargon: It’s great to be precise, but if the definition relies on another hard-to-define term, you’ve merely traded one mystery for another.

• Defining too broadly: A good definition is precise enough to distinguish the term from close cousins. If you blur the line with too wide a net, readers may misinterpret.

• Putting the definition out of reach: Don’t bury a crucial term’s meaning in footnotes or a distant glossary page. Link the definition where the term first appears, or provide a quick inline cue.

A practical workflow you can try

• Step 1: Identify the key terms readers will meet in your document.

• Step 2: Decide which def type fits each term based on where it appears and how much readers need to know upfront.

• Step 3: Draft a sentence definition for quick-reference terms.

• Step 4: Add expanded definitions for terms that might cause questions or are central to the workflow.

• Step 5: Where flow matters, pepper in parenthetical definitions sparingly.

• Step 6: Test with a reader who isn’t familiar with the product. Ask them to explain the term back to you. If they stumble, it’s a sign you’ve got work to do.

A few real-world touchstones

• Glossaries are your friend in long manuals and API docs. A well-organized glossary page with consistent definitions helps readers jump between sections with confidence.

• Style guides from groups like IEEE or industry associations often have preferred ways to present definitions. Borrow their clarity while adapting to your product’s voice.

• Documentation tools like DITA, MadCap Flare, or TraceMake often support glossary entries, term references, and inline definitions. They’re not just fancy bells and whistles; they’re practical aids for readers.

The reader’s experience matters

Definitions aren’t decorations. They’re the bridge from confusion to competence. Circular definitions break that bridge. The other approaches—sentence definitions, expanded definitions, and parenthetical definitions—provide a path readers can follow, one clear step at a time.

If you’ve ever read a paragraph and thought, “Okay, but what does that word mean here?” you’ve felt the power of a good definition. When you get them right, you notice the difference not just in compliance or accuracy, but in reader confidence. And that’s what clear technical writing is all about: helping people do what they need to do without getting tangled in language.

A final thought

Defining terms well is a small craft with a big payoff. It streamlines pages, speeds tasks, and reduces back-and-forth questions. The next time you sit down to write or revise, ask yourself: does this definition illuminate or leave the reader wandering? If the answer is illuminate, you’re likely using the right approach.

If you want a quick checklist to keep handy, here’s a compact version you can refer to as you draft:

• Is the term defined in plain language?

• Is the definition free of circular language?

• Do I provide an example or context where helpful?

• Is the definition placed near the first occurrence of the term?

• Have I kept the wording consistent with the glossary?

Clear definitions aren’t flashy, but they’re foundational. Treat them with care, and your technical writing will feel smoother, more trustworthy, and easier to use for everyone who reads it.