Dictionary.com
Thesaurus.com

phi

American  
[fahy] / faɪ /

noun

plural

phis
  1. the 21st letter of the Greek alphabet (Φ, φ).

  2. the consonant sound represented by this letter.


phi British  
/ faɪ /

noun

  1. the 21st letter in the Greek alphabet (Φ, φ), a consonant, transliterated as ph or f

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

One of these bizarre particles, called the phi meson, sits at the heart of these latest befuddling results.

From Scientific American • Feb. 2, 2023

Alpha, beta, upsilon, phi / Tuition here is too damn high!

From Seattle Times • Dec. 26, 2019

Alpha, beta, upsilon, phi / Tuition here is too damn high!

From Washington Times • Dec. 26, 2019

Having seen the alpha and omega of the series, I'm eager to see the gamma, delta, epsilon and phi, or whichever intermediate Greek letters you want to represent those four other episodes.

From Los Angeles Times • Feb. 13, 2019

It likewise appears that the Romans were for a long period unacquainted with the use of aspirates, and were destitute of the phi and chi sounds of the Greek alphabet.

From History of Roman Literature from its Earliest Period to the Augustan Age. Volume I by Dunlop, John