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Definition of phi

phi

/faɪ/
phi
Plural:phis
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phi Lexical Profile

phi Game Scores & Validity

• noun

1

The twenty-first letter of the Greek alphabet (Φ, φ), transliterated in the Roman alphabet as 'ph' or 'f'.

Example

"In physics formulas, the lowercase letter phi is frequently used to represent phase angles or magnetic flux."

2

In mathematics, the irrational number approximately equal to 1.618, commonly known as the golden ratio.

Example

"Architects and artists have long studied phi for its aesthetically pleasing geometric proportions."

Synonyms
View all synonyms for phi

• Rhymes for phi

• Nearby Words

phenomenon
pheromone
phew
phi
phial
philadelphia
philadelphian

Word Origin & Etymology

Borrowed from Latin phi, from Ancient Greek φῖ (phî), the name of the twenty-first letter of the Greek alphabet. In mathematics, the symbol φ was adopted in the early 20th century to represent the golden ratio after the ancient Greek sculptor Phidias.

Cite this Entry

Wordmom. (2026). Definition of Phi. In Wordmom Dictionary. Retrieved Nov 5, 2026, from https://wordmom.com/dictionary/phi
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