Xi Symbol
About Xi Symbol
ξ is the Xi Symbol, the lowercase form of the 14th letter of the Greek alphabet (Ξ / ξ). The Xi Symbol ξ is among the most common Greek letters in scientific and technical literature, frequently used for It appears as a random variable, damping ratio, and the xi particle in probability and high-energy physics.
【Pronunciation】 In English, ξ is most often pronounced ZYE or KSEE or SEE (IPA: /zaɪ, ksaɪ, saɪ/). This is simply the anglicized name of the Greek letter.
The lowercase Xi Symbol ξ is written as a distinct Greek glyph and is assigned codepoint U+03BE in the Greek and Coptic Unicode block. In plain or sans-serif fonts it can be mistaken for the Latin letter x, so verify the typeface or context.
【Historical Origin】 Xi derives from the Phoenician letter samekh and is relatively rare among Greek letters.
【Common Uses】 ξ is highly active across disciplines: It appears as a random variable, damping ratio, and the xi particle in probability and high-energy physics. It often appears alongside the uppercase Sigma Σ and lowercase Sigma σ in formulas, papers, and engineering drawings.
How to Type Xi Symbol
Windows Input
Method 1: Hold Alt and type 958 on the numeric keypad, then release Alt to get ξ.
Mac Input
Method 2: Press Control + Command + Space to open the Character Viewer, search for 'greek' or 'Xi Symbol', then select ξ.
HTML/CSS Input
Method 3: HTML: ξ or ξ or ξ; CSS: content: "\03BE";
LaTeX Input
Method 4: Use the \xi command in LaTeX math mode to produce ξ.
Xi Symbol FAQ
How is ξ pronounced?
The English pronunciation of ξ is ZYE or KSEE or SEE (IPA: /zaɪ, ksaɪ, saɪ/). It is the anglicized name of the Greek letter, used directly rather than described as 'lowercase ξ'.
What is the difference between ξ and the Latin letter x?
ξ (U+03BE) is a Greek lowercase letter, whereas x is a Latin letter; their codepoints and glyphs differ. In a proper typeface ξ and x are clearly distinct, but in plain text or sans-serif fonts they can be confused, so rely on context.
How do I type ξ in Word, web pages, and LaTeX?
On Windows use Alt+958 on the numeric keypad; on Mac open the Character Viewer and search 'greek' or 'Xi Symbol'; on the web use the HTML entity ξ; in LaTeX use \xi. For bulk use, copy ξ directly from this page.