What does analogy mean?
Analogy is a noun denoting a comparison between two things — often drawn from different domains — on the basis that their relationship or structure is similar, so that what holds true of one may illuminate the other. It is one of the most powerful tools of explanation: teachers use analogies to make abstract concepts concrete, scientists use them to model unfamiliar systems, and lawyers reason 'by analogy' from precedent cases to new ones. A well-chosen analogy can make a difficult idea instantly graspable, such as comparing the flow of electricity to the flow of water through pipes. However, analogies are inherently imperfect, and extending one too far produces the 'false analogy' fallacy, so careful thinkers treat analogies as guides rather than proofs. The word derives from Greek 'analogia', meaning proportion, and entered English in the sixteenth century, initially in mathematical and logical contexts before broadening into general use.
nounA comparison between two things, typically for the purpose of explanation or clarification, based on the idea that if they are alike in some respects they will be alike in others.
- A comparison between two things based on shared structure or relationship, used to explain or clarify an unfamiliar idea in terms of a familiar one.
- In logic and mathematics: a relation of similarity or proportionality between two systems or sets of relations (e.g. 'the analogy of being' in philosophy; proportional analogy in mathematics).
- In biology: similarity of function between structures of different origin (analogous organs), as opposed to homology.
"The teacher used an analogy between a battery and a water pump to explain how electric current flows."
"She explained the national debt by drawing an analogy with a household budget."
"In his letter to the Romans, Paul reasoned by analogy from human relationships to describe God's dealings with humanity."
Standard plural; commonly used when discussing multiple comparisons, e.g. in teaching or scientific writing.
"The textbook presented several analogies to illustrate cell division."
The word 'analogy' comes from Greek 'analogia' — meaning 'proportion' — and was originally a mathematical term before philosophers borrowed it to explain ideas by comparing them to familiar things.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of analogy
Analogy comes from Greek 'analogia', meaning 'proportion' or 'mathematical ratio', formed from 'ana-' ('according to') and 'logos' ('ratio, reckoning'). It was adopted into Latin as 'analogia' and entered English in the sixteenth century, at first chiefly in mathematics and logic before expanding into rhetoric, theology, and ordinary explanatory language. It shares its Greek root '-logia' element with words such as biology, psychology, geology, and apology, though those derive from different compound formations.
Related word forms
How analogy is actually used
Analogy is a neutral-to-formal word common in education, science, law, theology, and everyday explanation. In argumentation, 'a false analogy' is a recognized fallacy, so invoking an analogy carries some burden of justification. The plural is standard.
Easily confused with analogy
An analogue is something that corresponds to or resembles another thing (or refers to non-digital technology), whereas an analogy is the comparison or reasoning itself.
A metaphor directly states that one thing is another in figurative language, while an analogy explicitly compares two things that remain distinct but share a structural relationship.