≝
Unicode
U+225DLaTeX
\stackrel{def}{=}HTML entity
≝HTML decimal
≝MathML
<mo>≝</mo>Semantic identity and intent
Characters to distinguish
- ≔ — Colon Equals
Use ≝ in the right format
Meaning and usage
States that one expression is defined to equal another expression.
Use it at the point a new symbol, function, or quantity is introduced.
Pronunciation: equal to by definition
Formula examples
c≝a+bHow to type Equal To by Definition
- Windows
- Use Character Map or enter U+225D in a Unicode-aware application.
- macOS
- Open Character Viewer with Control–Command–Space and search by the symbol name.
- Microsoft Word
- In an equation, type \stackrel{def}{=} and press Space when Word supports the command.
- iPhone and iPad
- Copy and paste ≝, or use a math/LaTeX app. The standard iOS keyboard may not expose every mathematical symbol.
- Android
- Copy and paste ≝, or use a math keyboard or LaTeX editor. Keyboard layouts vary by device and app.
- Google Docs
- For plain text, paste ≝ or use Insert → Special characters. For structured math, use the equation editor and verify \stackrel{def}{=}.
- Excel
- Paste ≝ into a cell or use Insert → Symbol when available. Ordinary cells preserve the character but do not interpret LaTeX commands.
Common mistakes
- Preserve grouping, operator order, and spacing around ≝; Use it at the point a new symbol, function, or quantity is introduced.
- For plain text, copy ≝ as U+225D; for structured equations, use \stackrel{def}{=} in math mode. A look-alike glyph or image can break search, accessibility, or parsing when the intended character is Equal To by Definition.
When to use ≝
- Use ≝ in plain text when a Unicode character is appropriate and the destination preserves U+225D.
- Use \stackrel{def}{=} in an equation editor when mathematical spacing or structure matters.
- Define the local meaning when Equal To by Definition is used in comparison, algebra with a field-specific convention.
Look-alikes and related characters
- ≔ — Colon Equals
Font and compatibility notes
Glyph shape can vary by font. Verify the code point after copying, and prefer LaTeX or MathML for structured equations.
Continue the workflow
From Equal To by Definition to a finished equation
- Copy the characterUse ≝ in plain text when Unicode is accepted.
- Choose a structured formatUse
\stackrel{def}{=}for LaTeX or the MathML snippet for accessible web equations. - Edit or convertOpen the value in the editor or converter without retyping it.
Review and source notes
Quality tier: specialist
Last reviewed: 2026-07-23
Review method: Catalog review of character identity and notation mappings.
Verified against: Unicode Standard, Unicode mathematical notation guidance, and established LaTeX/MathML syntax.
Reference sources
- The Unicode StandardUnicode Consortium — Character identity, encoding, names, and conformance.
- Unicode Character Code ChartsUnicode Consortium — Code points and official character charts.
Frequently asked questions
What does the Equal To by Definition symbol mean?
States that one expression is defined to equal another expression.
What is the LaTeX command for ≝?
Use \stackrel{def}{=} in a compatible math environment.
Can I copy ≝ as Unicode?
Yes. Use the copy button above to copy the Unicode character directly.