noun
Common
xi
zeye
Xi (noun) means a letter of the Greek alphabet (Ξ, ξ), used in math and science to represent variables or particles. Example: “The professor wrote xi on the board and asked us to solve for it.”
noun
1
A letter of the Greek alphabet (Ξ, ξ), used in math and science to represent variables or particles.
"The professor wrote xi on the board and asked us to solve for it."
"In physics, the xi particle is named after a Greek letter."
"The equation used xi to represent the unknown angle."
2
A sports team made up of eleven players, especially in football (soccer) or cricket.
"The manager changed two players but kept the same xi for the cup final."
"Fans argued online about who deserved a place in the national xi."
"The coach named his starting xi an hour before kickoff."
How to use xi
Learner’s notesIn plain EnglishEither the Greek letter xi, or British sporting shorthand for a team of eleven.
UK vs US
"The first xi" (meaning the starting team) is common British sporting terminology, less used in American English.
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Word forms
- Plural
- xis
Fill the gap
Can you complete this real example?
The professor wrote _____ on the board and asked us to solve for it.
Etymology
From the Ancient Greek letter name xeî/xî.
Related words
Frequently asked questions
What does “xi” mean?
The word “xi” means a letter of the Greek alphabet (Ξ, ξ), used in math and science to represent variables or particles. In plain terms, either the Greek letter xi, or British sporting shorthand for a team of eleven.
How do you pronounce “xi”?
“Xi” is pronounced zeye (/zaɪ/ in IPA).
How do you use “xi” in a sentence?
Here is “xi” used in a sentence: “The equation used xi to represent the unknown angle.”
What part of speech is “xi”?
“Xi” is a noun.
Where does the word “xi” come from?
The word “xi” comes from Ancient Greek. From the Ancient Greek letter name xeî/xî.
Is “xi” a common word?
“Xi” is a fairly common word in modern English.
How many meanings does “xi” have?
“Xi” has 2 distinct senses listed in this dictionary. The most common is: a letter of the Greek alphabet (Ξ, ξ), used in math and science to represent variables or particles.
What is the difference between xi and chi in the Greek alphabet?
Xi and chi are two separate letters of the Greek alphabet. Xi is written Ξ or ξ, while chi is written Χ or χ. They look and sound different, and both are used in maths and science to stand for variables or quantities.
Why is a football or cricket team called an XI?
An XI is a sports team made up of eleven players, especially in football (soccer) and cricket, since each side fields eleven. XI is the Roman numeral for eleven, which is where the name comes from. A club may talk about its 'first XI' as its main team.
Is xi written in capital or lowercase letters?
As the Greek letter, it can be uppercase Ξ or lowercase ξ, depending on what it represents in a formula. As a sports team of eleven, it is usually written as the Roman numeral XI in capitals. The two uses look quite different on the page.
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