Dictionary
Thesaurus
Medical
Scrabble®
Spanish Central
Browse DictionaryBrowse Thesaurus
Get our free apps!iPhone•iPad•Android
Games
Word of the Day
Video
Blog: Words at Play
My Faves
Dictionary

phi

noun \ˈfī\

Definition of PHI

:  the 21st letter of the Greek alphabet — see alphabet table
See phi defined for kids
ADVERTISEMENT

Origin of PHI

Middle Greek, from Greek phei
First Known Use: 1638

Rhymes with PHI

ay, aye, bi, Bligh, buy, by, bye, chai, chi, cry, die, dry, dye, eye, fie, fly, fry, guy, hie, high, Huai, i, I, lie, lye, my, nigh, pi, pie, ply, pry, psi, rye, scythe, shy, sigh, sky, Skye, sly, spry, spy, sty, Tai, Thai, thigh, thy, tie, try, vie, why, wry, wye, xi, Y

Learn More About PHI

Browse

5 ENTRIES FOUND:
  1. phi
  2. Phi Beta Kappa
  3. Phi Bete
  4. phi phenomenon
  5. Phi Tong Luang
Next Word in the Dictionary: phialPrevious Word in the Dictionary: phewAll Words Near: phi
ADVERTISEMENT
10 Charming Words for Nasty People
Put-downs with flair
Learn More
When "Literally" isn't, well, literal
How to use a word that (literally) drives some people nuts.
Watch Now
Know what this is?
Test your vocab with our fun, fast game
Go Play
Fear of cats?
Ailurophobia, and 9 other unusual fears
Learn More
Join Us
Merriam-Webster
on Facebook
Merriam-Webster
on Twitter
Bookstore: Digital and Print
Merriam-Webster references for Mobile, Kindle, print, and more.
See All
Other Merriam-Webster Dictionaries