There is a total of 31380 clues beginning with on
- Only Great Lake that borders Pennsylvania
- Only group with elements in all three states of matter at room temperature
- Only guest host in the 21 years of Leno's "The Tonight Show"
- Only half
- Only half-pretentious?
- Only have eyes for
- Only head coach in six Super Bowls
- Only highest grossing film of the year to run at a loss
- Only highest-grossing film of the year that lost money
- Only hip-hop group that performed at Live Aid
- Only his tail was left after a brawl
- Only Hispanic performer with an Emmy, Grammy, Oscar and Tony
- Only hit song for which title and artist are both palindromes
- Only Hitchcock film to get a Best Picture Oscar
- Only Hitchcock film to win Best Picture
- Only horse to beat Man o' War
- Only host country to win the Women's World Cup
- Only human, briefly
- Only humans shed these
- Only Huxtable boy
- Only hypothetical
- Only if
- Only if it's worth the trade-off
- Only Illinois-born President
- Only in the past
- Only inanimate zodiac representation
- Only inanimate zodiac sign
- Only inanimate zodiac symbol
- Only Indonesian province with a Hindu majority
- Only Indonesian-speaking President
- Only inductee into both the Rock and Roll Hall of Fame and the National Inventors Hall of Fame
- Only ingredient in Accent, in brief
- Only insects that can turn their heads to look behind them
- Only its Touch model is currently sold
- Only Japanese MLB player to pitch a no-hitter (he had two)
- Only Jet who was a Super Bowl MVP
- Only just
- Only just broke the tape
- Only just get, with "out"
- Only just managed (with "out")
- Only just managed, with "out"
- Only just
- Only key Irving Berlin composed in
- Only landlocked country in Southeast Asia
- Only last name shared by two different Best Actor Oscar winners
- Only Literature Nobelist also to win an Oscar
- Only living species of its genus
- Only living thing that can be seen from outer space
- Only lizards to have voices
- Only look
- Only MLB team never to have played in a World Series
- Only MLB team that Johnny Bench played for (1967-83)
- Only main “Seinfeld” character who was not in the show’s pilot episode
- Only major "M*A*S*H" character played by the same actor in the film and TV series
- Only major league team without a no-hitter to its credit
- Only major tourney that Sam Snead failed to win
- Only major US city bisected by a mountain range
- Only major US city with a radio station whose call letters spell the city's name
- Only major-league player to enter the 3,000-hit club in the 1980s
- Only make-believe
- Only making the grade?
- Only male player with more French Open crowns than Borg
- Only male singles Career Golden Slam winner
- Only mammal capable of true flight
- Only mammal with horns made of keratin
- Only mammals capable of true flight
- Only man ever to win an LPGA Tour tournament (1962)
- Only man to be US Pres and Chief Jst
- Only man to be US President and Chief Justice
- Only man to fly in Mercury, Gemini and Apollo missions
- Only man to pitch 17 Across twice in a row (1938)
- Only man to serve as US President and Chief Justice of the Supreme Court
- Only man to twice win the US Open without losing a set in the entire tournament
- Only man to win both a Nobel Prize and an Oscar
- Only man to win two tennis Grand Slams
- Only marsupial native to the Americas
- Only matchmaker in town?
- Only member of both OPEC and the British Commonwealth
- Only men's basketball coach to lead three different schools to the NCAA Final Four
- Only Met ever to have a 30-game hitting streak
- Only metal that's liquid at room temperature
- Only Mexican state that borders Baja
- Only mildly sweet
- Only million-selling Beatles single that was a cover
- Only minimally
- Only Mississippi-born Literature Nobelist
- Only mo all four major sports are played
- Only mo that can begin and end on the same day
- Only mo that can begin and end on the same day of the week
- Only mo that can pass without a single full moon
- Only mo that can start and end on the same day
- Only mo without a holiday
- Only money accepted at the Sky Mall?
- Only monosyllabic state
- Only monosyllabic US state
- Only month that starts on a Sunday in 2021
- Only mortal Gorgon in Greek myth
- Only Mouseketeer personally chosen by Walt Disney
- Only movie for which John Wayne won an Oscar
- Only moving part of a Tesla engine