Qua definitione
“By virtue of definition.”
Scholarly Latin
What does “Qua definitione” mean?
Qua definitione translates as “By virtue of definition.”
Something is true simply because of how a term is defined.
“Qua definitione” word by word
| Latin | English | Grammar |
|---|---|---|
| Qua | by which, by way of which | ablative singular feminine of the relative pronoun qui, quae, quod; it agrees with definitione and here has a loose “in accordance with” force |
| definitione | definition | ablative singular of definitio, definitionis (feminine), “a definition”; ablative of means or manner |
How to pronounce “Qua definitione”
The two differ mainly in the middle: Classical has a hard t (nih-tee-OH), while Church Latin softens ti before a vowel to tsee (nee-tsee-OH). Stress falls on the first syllable of qua and on the second-to-last syllable of definitione.
The story behind it
Word for word the phrase says “by which definition”, and it is used to mean “by definition”: something holds because of how the term is defined, not because of any evidence. Qua is the relative pronoun in the ablative, here working almost like a preposition.
It is not a phrase from ancient Roman authors. It is scholarly Latin of the modern period, equivalent to the more common per definitionem, and it is found chiefly in academic writing in German-speaking countries.
The usual English counterpart is “by definition”. Logicians and philosophers use such wording for statements that are true simply because of the meaning of their terms.
How to use “Qua definitione”
Best suited to an academic or witty context: a footnote or essay aside, a caption for a philosophy or logic joke, or a motto for someone who loves precise terms. As a tattoo it is quite obscure and will need explaining.
- Latin
- Qua definitione
- English
- By virtue of definition.
- Source
- Scholarly Latin
- Era
- Modern
- Theme
- Learning
Common mistakes
- It does not mean “who defines” or “what definition?”. Qua is not a question word here.
- Do not swap in per definitionem and expect the same wording. It means the same thing, but it is a different, more widely used phrase.
- It is not classical Latin, so do not attribute it to Cicero or any other ancient author.
- Qua can also be a conjunction meaning “as” (qua philosopher, “in the role of a philosopher”). Here it is simply the ablative relative pronoun.
Questions about “Qua definitione”
What does “Qua definitione” mean literally?
Literally “by which definition”, used in the sense “by definition”: true because of how the term is defined.
Who said “Qua definitione”?
No one in particular. It is a modern scholarly phrase, not a quotation from an ancient author.
How do you pronounce “Qua definitione”?
Classically KWAH deh-fih-nih-tee-OH-neh. In Church Latin the middle softens to deh-fee-nee-tsee-OH-neh.
Is “Qua definitione” the same as “per definitionem”?
In meaning, yes: both express “by definition”. Per definitionem is the more common form, while qua definitione is used chiefly in German-speaking academic contexts.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
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