A clear analogy definition is "a comparison between two different things that shows how they are alike in some useful way, usually to explain an idea." When a teacher says the heart works like a pump, she is using an analogy: the familiar pump helps you picture the less familiar heart.
Analogies appear in classrooms, sales pitches, courtrooms and entrance exams. Here is the meaning of analogy, how it differs from a metaphor or simile, and how to build a good one yourself.
Entry at a glance
Meaning
A comparison showing a likeness between two things, often to explainPart of speech
Noun (plural: analogies)Pronunciation
uh-NAL-uh-jeeWord forms
analogous (adjective), analogical, analogicallyOrigin
Greek analogia, proportion, via Latin and FrenchClose words
comparison, parallel, likenessRegister
Neutral; common in teaching, writing and argument
The meaning of analogy, step by step
An analogy has three working parts:
- Something you want to explain (the target), such as how a computer's memory works.
- Something familiar (the source), such as a desk.
- The shared pattern: the desk surface is like short-term memory, where you keep what you are using now, and the filing cabinet is like long-term storage.
The goal is not to say the two things are the same. It is to borrow the structure of something easy to understand and lay it over something harder. That is why analogies often run for several sentences, while a metaphor may be a single phrase.
Examples of analogies
- Explaining a firewall: it is like a security guard at a building's entrance, checking who gets in and who gets turned away.
- A coach to a nervous team: training is like saving money; small deposits every day add up when you need them most.
- In biology class: DNA is like a recipe book, and each gene is one recipe for making a protein.
- A parent to a teen: a credit score is like a reputation at school; it takes years to build and one bad week to damage.
Analogy vs metaphor vs simile
| Device | What it does | Sample |
|---|---|---|
| Simile | Draws the link with like or as | Her voice was as soft as rain. |
| Metaphor | Treats one thing as if it were another | The classroom was a zoo. |
| Analogy | Explains by mapping a whole pattern from one thing to another | Learning a language is like learning to swim: reading about it only goes so far. |
Similes and metaphors can be the building blocks of an analogy, but an analogy usually has a job beyond decoration: to explain or to argue. For an extended story that stands for a deeper idea, see allegory.
Analogy questions on tests
Many school and entrance exams use word analogies written like this: glove : hand :: sock : foot. Read it as "glove is to hand as sock is to foot." You must find the relationship in the first pair and pick the pair that matches it. Common relationships include:
- Part to whole: petal : flower
- Tool to user: scalpel : surgeon
- Cause to effect: rain : flood
- Degree: warm : hot
Tip: say the relationship as a full sentence ("a glove covers a hand") before looking at the answer options.
Origin and history of the word
Analogy comes from the Greek analogia, which meant proportion, built from ana (according to) and logos (ratio or reason). Greek mathematicians used it for equal ratios, such as 2 is to 4 as 3 is to 6. English took the word through Latin and French, and its meaning widened from maths to any kind of reasoned likeness.
Analogy definition in science and law
In biology, analogous structures do the same job but evolved separately, like the wings of a bird and the wings of a butterfly. In law, arguing by analogy means saying a new case should be decided like an earlier, similar one. In everyday reasoning, analogy helps us make an inference about something new from something we know. The risk is a false analogy, where two things look alike but differ in the way that matters.
How to write a strong analogy
- Pick a source your audience already knows well.
- Match the important feature, not just a surface look.
- Keep it short, then explain where the comparison stops.
- Avoid stretching one analogy across a whole essay.
Writers will find similar tools among our grammar and writing terms.
Frequently asked questions
Can you give an analogy definition in one line?
An analogy is a comparison that explains something by showing how it is similar to something else. It is often used to make a hard idea easier to grasp.
How do you define analogy for kids?
You can say an analogy is when you explain something new by saying it works like something they already know. For example, the skin is like a raincoat that keeps germs out.
Is every simile an analogy?
Not quite. A simile is a quick comparison using like or as, often for description. It becomes an analogy when it explains how something works or supports an argument by matching a deeper pattern.
What is a false analogy?
It is a comparison that sounds convincing but fails because the two things differ in the way that matters. Saying a country should be run exactly like a household budget is a common example people argue about.
How do you pronounce analogy?
Say uh-NAL-uh-jee; the NAL part is loudest. The adjective analogous is uh-NAL-uh-gus, with a hard g.
What does analogous mean?
Analogous means similar in a way that allows comparison. Two situations are analogous if what you learn from one can help you understand the other.