| PHI | "Golden ratio" symbol which is an anagram of "hip" |
| PHI | #21 of 24 |
| PHI | 21st Greek letter |
| PHI | 21st chapter of a frat |
| PHI | 21st in a series of 24 |
| PHI | 21st letter |
| PHI | 21st letter in the Greek alphabet |
| PHI | 21st letter of the Greek alphabet |
| PHI | 21st of 24 |
| PHI | 76ers, on scoreboards |
| PHI | Abbreviation seen during 76ers games |
| PHI | Ancient excerpt from Aristophanes |
| PHI | Angle symbol |
| PHI | Another fraternity letter |
| PHI | Apt Greek letter for a University of Pennsylvania fraternity |
| PHI | Beta Kappa |
| PHI | Beta Kappa preceder |
| PHI | Beta Kappa starter |
| PHI | Beta preceder |
| PHI | Beta preceder in the fraternity group |
| PHI | Campus letter |
| PHI | Chi preceder |
| PHI | City home to Independence Hall (Abbr.) |
| PHI | College key letter |
| PHI | Common fraternity letter |
| PHI | Eagles, for short |
| PHI | Electric flux symbol |
| PHI | F in Greek |
| PHI | F, in Greek life |
| PHI | Feta was originally spelled with one |
| PHI | First Greek letter in Phobos |
| PHI | First letter of the academic honor society |
| PHI | Fluidity symbol, in mechanics |
| PHI | Flyers, on scoreboards |
| PHI | Follower of upsilon |
| PHI | Fourth-to-last Greek letter |
| PHI | Frat letter |
| PHI | Fraternal letter |
| PHI | Fraternity character |
| PHI | Fraternity letter |
| PHI | Fraternity letter after "upsilon" |
| PHI | Fraternity letter that follows upsilon |
| PHI | Golden Ratio symbol |
| PHI | Golden ratio |
| PHI | Golden ratio letter |
| PHI | Golden ratio symbol |
| PHI | Gr. letter |
| PHI | Greek "F" |
| PHI | Greek "f" |
| PHI | Greek consonant |
| PHI | Greek letter |
| PHI | Greek letter a bit like F |
| PHI | Greek letter after upsilon |
| PHI | Greek letter associated with the 33-Across |
| PHI | Greek letter before chi |
| PHI | Greek letter between upsilon and chi |
| PHI | Greek letter in a sorority name, perhaps |
| PHI | Greek letter often used to denote angles |
| PHI | Greek letter that looks like an I and O superimposed |
| PHI | Greek letter that represents the golden ratio |
| PHI | Greek letter that sounds like "fie" |
| PHI | Greek letter that sounds like fi |
| PHI | Greek letter that's also an M.L.B. city on scoreboards |
| PHI | Greek letter used for plane angles |
| PHI | Greek letter used to represent magnetic flux |
| PHI | Greek letter, equivalent to F |
| PHI | Greek letter, or the first three letters of a Pennsylvania city |
| PHI | Greek sorority letter |
| PHI | Greek symbol for the golden ratio |
| PHI | Gritty's squad, on a scoreboard |
| PHI | Gritty's team, on scoreboards |
| PHI | Honor society character |
| PHI | Honor society letter |
| PHI | Honor society opening |
| PHI | Honor society starter |
| PHI | Honorary letter |
| PHI | Honorary society letter |
| PHI | It's three after 3-Down |
| PHI | It's written as a vertical line bisecting a circle |
| PHI | Key letter |
| PHI | Key letter? |
| PHI | Key opener? |
| PHI | Letter after upsilon |
| PHI | Letter before 35-Across |
| PHI | Letter before Beta in a society's name |
| PHI | Letter before chi |
| PHI | Letter for Plato |
| PHI | Letter for Socrates |
| PHI | Letter from Athens |
| PHI | Letter in an honor society's name |
| PHI | Letter in some sorority names |
| PHI | Letter of Greek alphabet |
| PHI | Letter on a sorority sister's T-shirt, perhaps |
| PHI | Letter on an honor society key |
| PHI | Letter on some gold keys |
| PHI | Letter seen twice in Philadelphia |
| PHI | Letter that may have derived from the Phoenician qoph |
| PHI | Letter that resembles the "y" of Disney's signature |
| PHI | Letter that rhymes with the two that follow it |
| PHI | Letter three before 15-Across |
| PHI | Letter two after tau |
| PHI | Magnetic flux symbol |
| PHI | Mathematician's golden ratio symbol |
| PHI | N.L. East team |
| PHI | N.L. East team, on scoreboards |
| PHI | NBA Sixers, on scoreboards |
| PHI | NL East team |
| PHI | One of five rhyming Greek letters |
| PHI | Pa. team, on scoreboards |
| PHI | Penn. ball team, on scoreboards |
| PHI | Preantepenultimate letter |
| PHI | Repeat twice for a Thai island group |
| PHI | Sixers, on a scoreboard |
| PHI | Sorority character |
| PHI | Sorority letter |
| PHI | Symbol for electric flux, in physics |
| PHI | Symbol for magnetic flux |
| PHI | Symbol for the golden ratio |
| PHI | Symbol of electric flux |
| PHI | Symbol of latitude |
| PHI | Symbol of the golden ratio |
| PHI | Symbol used in spherical coordinates |
| PHI | The 76ers, on scoreboards |
| PHI | The Eagles or Flyers, on scoreboards |
| PHI | The Eagles or the Sixers, on a scoreboard |
| PHI | The Eagles, for short |
| PHI | The Eagles, on a scoreboard |
| PHI | The Eagles, on scoreboards |
| PHI | The Flyers or 76ers, on scoreboards |
| PHI | The Greek 1.618 |
| PHI | The Greeks spell "feta" with one |
| PHI | The NBA's 76ers, on a scoreboard |
| PHI | The NBA's 76ers, on scoreboards |
| PHI | The NBA's Sixers, on scoreboards (Abbr.) |
| PHI | The NFL's Eagles, on a sports news crawl |
| PHI | The NFL's Eagles, on scoreboards |
| PHI | The NFL's Eagles, on sports tickers |
| PHI | The NHL's Flyers, on scoreboards |
| PHI | The Sixers, on scoreboards |
| PHI | The golden ratio |
| PHI | The golden ratio symbol |
| PHI | Twenty-first Greek letter |
| PHI | Upsilon chaser |
| PHI | Upsilon follower |
| PHI | Upsilon's follower |
| PHI | Upsilon's successor |
| PHI | When doubled, an island group in Thailand |
| PHI | When repeated it's an island group in Thailand |
| PHI | When repeated twice, an island group in Thailand |
| PHI | When repeated, Thai islands popular with tourists |
| PHI | When repeated, an island group in Thailand |
| PHI | When repeated, it's an island group in Thailand |
| PHI | When repeated, it's the name of an island group in Thailand |
| PHI | Zeta ___ Beta |
| PHI | __ Beta Kappa |
| PHI | ___ Beta Gamma |
| PHI | ___ Beta Kappa |
| PHI | ___ Beta Kappa (College honor society) |
| PHI | ___ Beta Kappa (academic group) |
| PHI | ___ Beta Kappa (academic honor group) |
| PHI | ___ Beta Kappa (academic honor society) |
| PHI | ___ Beta Kappa (academic society) |
| PHI | ___ Beta Kappa (college honor society) |
| PHI | ___ Beta Kappa (college society) |
| PHI | ___ Beta Kappa (collegiate honor society) |
| PHI | ___ Beta Kappa (group for students) |
| PHI | ___ Beta Kappa (honor society founded in 1776) |
| PHI | ___ Beta Kappa (honor society in the US) |
| PHI | ___ Beta Kappa (honor society) |
| PHI | ___ Beta Kappa (oldest academic honor society) |
| PHI | ___ Beta Kappa (prestigious honor society) |
| PHI | ___ Beta Kappa (scholars' group) |
| PHI | ___ Beta Kappa (scholastic honor society) |
| PHI | ___ Beta Kappa (students' honor society) |
| PHI | ___ Beta Kappa Society |
| PHI | ___ Beta Kappa Society, the oldest American academic honor society |
| PHI | ___ Beta Kappa, academic fraternity |
| PHI | ___ Beta Kappa, academic honor society in the USA |
| PHI | ___ Beta Kappa, the most prestigious academic honor society in the United States |
| PHI | ___ Beta Kapppa |
| PHI | ___ Bete (honor society member, informally) |
| PHI | ___ beta kappa |
| PHI | ___ phenomenon (optical illusion) |
| PHI | ___, Beta, Kappa |
| PHI | ___, beta, kappa |
| PHI | ___Beta Kappa |
| PHI | ____ Beta Kappa |
| PHI | _____ Beta Kappa |
| PHI | — Beta Kappa |