Quick intro
Per definition is a short phrase people see in writing, and it often raises questions about correctness and clarity. Some writers use it confidently, others suspect it is awkward or nonstandard. Which side is right?
This piece looks at where the phrase comes from, how people use it, and when you might choose an alternative for clearer English. Think of it as a friendly language check, with examples and small history notes along the way.
Table of Contents
What Does per definition Mean?
At its core, per definition means roughly “according to the definition” or “by the definition.” Writers use it when they want to tie a statement directly to a formal or agreed definition. It functions as a linking phrase that signals the source of a claim is a definition rather than observation or evidence.
In many cases you can replace per definition with by definition or according to the definition without changing the sense. But usage and tone differ, and those differences matter in careful writing.
Etymology and Origin of per definition
The phrase combines Latin-derived per, meaning “through” or “according to,” with the noun definition, from Latin definire, meaning “to set limits.” That composition is straightforward and not mysterious.
What complicates matters is that per definition pops up more often in translation contexts or in varieties of English influenced by other languages. For example, German speakers sometimes say per Definition, and that structure can carry over into English usage. Language contact explains some of the phrase’s spread.
How per definition Is Used in Everyday Language
Writers use per definition in academic, legal, and business contexts when a claim is meant to rest strictly on a definitional point. It crops up in emails, reports, and sometimes in everyday speech among people who like precise phrasing.
Below are real-style examples showing how the phrase appears in context. Some of these would sound perfectly fine to many readers, others might strike a reader as slightly formal or translated.
1. “Per definition, a triangle has three sides, so this figure cannot be called a triangle.”
2. “Per definition of our policy, refunds are only granted within 14 days of purchase.”
3. “Per definition, the term ‘eligible claimant’ includes anyone who meets the listed criteria.”
4. “You could say, per definition, that an even number is divisible by two without remainder.”
Each example is grammatically fine. The tone ranges from textbook to bureaucratic, which is part of why some readers prefer alternatives.
per definition in Different Contexts
In formal writing such as legal drafts or technical manuals, per definition works because it directly ties a claim to an agreed statement. Lawyers and policy writers sometimes prefer that flat, unambiguous phrasing.
In conversational English, per definition can sound stiff or translated. Most native speakers would reach for by definition or simply state the definitional fact without a linking phrase. In creative writing it can feel wooden unless used deliberately for voice.
In international business and academic English, the phrase appears more often, especially among non-native speakers. There it serves a clear function: pointing to a definition as the authority for a claim.
Common Misconceptions About per definition
A common misconception is that per definition is flat-out wrong. It is not inherently ungrammatical. The problem is pragmatic: it may signal an unnatural register or a literal translation from another language.
Another misconception is that per definition is interchangeable with per se. They are not. Per se means “in itself” or “by itself,” while per definition ties a claim to an explicit definition. Confusing them changes the meaning.
Related Words and Phrases
If you want alternatives, try by definition, according to the definition, as defined, or by that definition. Each option carries slightly different tone and scope.
Use by definition when you want a natural, idiomatic English phrasing. Use according to the definition when you want to emphasize the source or document that contains the definition. Use per definition sparingly if you need a flat, technical tone or when mirroring source language makes sense.
For more on the idea of definition itself, see Merriam-Webster’s entry on definition and the philosophical perspective at Britannica. A helpful overview is also available on Wikipedia.
Why per definition Matters in 2026
Language shifts quickly. Global collaboration means more writers whose native languages influence English habits. Per definition is a small example of how cross-lingual influence changes phrasing and sparks style debates.
Writers and editors still care about clarity. Choosing between per definition, by definition, and other options affects tone. In legal and technical contexts, that choice can also affect interpretation, so it is not merely stylistic.
Knowing the nuance helps you pick the right phrase for your audience. Want terseness and authority? per definition may do. Want conversational ease? Choose by definition.
Closing thoughts
Per definition is a serviceable phrase that links a claim to a definition. It is not verboten, but it does carry register and origin baggage. Use it when you need a formal, direct pointer to a definition, and consider simpler alternatives for general prose.
Language is full of small choices like this one. Paying attention to them makes writing clearer and more persuasive, whether you are drafting a memo, teaching a class, or polishing a novel chapter.
For related guidance on similar phrases, see definition meaning and by definition meaning on AZDictionary.