There is a total of 85689 clues beginning with o
- One of the Chicago Eight
- One of the chief Philippine dialects
- One of the chief seaports of Samoa
- One of the Chinas
- One of The Chipmunks
- One of the choices on a computer's 17-Across
- One of the Churchills
- One of the Churchills
- One of the Cinque Ports
- One of the Cinque Ports, in Sussex
- One of the Cinque Ports, Sussex
- One of the Cinque ports
- One of the CIO's first members
- One of the Cities of the Plain
- One of the clan
- One of the Clanton boys
- One of the Clanton brothers
- One of the Clantons
- One of the Claremont Colleges
- One of the Clarks
- One of the classes
- One of the classical architectural orders
- One of the classical elements
- One of the classical orders of architecture
- One of the classics
- One of the classics
- One of the Clauses
- One of the Cleavers
- One of the clefs
- One of the clergy
- One of the Clintons
- One of the clubs
- One of the Clue weapons
- One of the co-founders of Wikipedia
- One of the coasts
- One of the coasts: Abbr
- One of the Coen brothers
- One of the Coens
- One of the Collier brothers, for instance
- One of the Collinses
- One of the Colonial Colleges, informally
- One of the Colonies: Abbr
- One of the colorful Vatican troops
- One of the common folk
- One of the common people
- One of the common people
- One of the common people: Slang
- One of the components of an MLB Triple Crown
- One of the compound spots on a leopard
- One of the conglomerates
- One of the conifers
- One of the Conners on "Roseanne"
- One of the conspirators against Caesar
- One of the continents
- One of the continents: Abbr
- One of the convicted Rosenberg spies
- One of the Cook Islands
- One of the Cook Islands, near New Zealand
- One of the Cook Islands, off New Zealand
- One of the Cook Islands
- One of the Coolidges
- One of the Coppolas
- One of the Coreys on "The Two Coreys"
- One of the Corleone boys
- One of the Corleones
- One of the Corleones (FOR ED anag)
- One of the Corleones in "The Godfather"
- One of the Corleones of fiction
- One of the corners at Four Corners Monument
- One of the corps
- One of the Cosby kids
- One of the Costanzas, on "Seinfeld"
- One of the Cowards
- One of the Cowboys, for short
- One of the Crane brothers
- One of the Cranes
- One of the Cratchits
- One of the Cratchits
- One of the Crawleys, in "Vanity Fair"
- One of the creators of the land of Midgard
- One of the crew
- One of the Crimeans
- One of the crowd, in a movie
- One of the crowd, perhaps
- One of the crowd?
- One of the crows
- One of the Crusader states
- One of the Culkin brothers
- One of the Curies
- One of the Curies
- One of the currencies replaced by the euro in 2002
- One of the current heavyweights
- One of the Cyclades
- One of the Cyclades islands
- One of the Cyclades Islands
- One of the Cyclades
- One of the Cyclades: It name
- One of the czars
- One of the d's in "3-D"
- One of the D's in 35-Across