: the 21st letter of the Greek alphabet see Alphabet Table

Word History


Middle Greek, from Greek phei

First Known Use

15th century, in the meaning defined above

Time Traveler
The first known use of phi was in the 15th century

Dictionary Entries Near phi

Cite this Entry

“Phi.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phi. Accessed 4 Oct. 2023.

Kids Definition


: the 21st letter of the Greek alphabet
Φ or φ

More from Merriam-Webster on phi

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