There is a total of 6422 clues beginning with op
- Opponent for Martina or Monica
- Opponent for Minnesota Fats
- Opponent for Monica
- Opponent for the Bosox
- Opponent in an argument
- Opponent in battle
- Opponent in blackjack
- Opponent in business or sports
- Opponent in Risk
- Opponent in Risk or Stratego
- Opponent of
- Opponent of "Home," on a scoreboard
- Opponent of "us"
- Opponent of 120-Across
- Opponent of 122 Down
- Opponent of 14-Down, in sports
- Opponent of 28-Across
- Opponent of 28-Down, in comics
- Opponent of 3-Down, in Greek myth
- Opponent of 40 Down
- Opponent of 40 Down
- Opponent of 49-Down, in film
- Opponent of 64-Down, in the Bible
- Opponent of 78-Down, in fable
- Opponent of 85 Across
- Opponent of 86-Down, in games
- Opponent of 9-Down, in classical literature
- Opponent of AES
- Opponent of Arab League
- Opponent of Balboa
- Opponent of Brutus
- Opponent of Caesar
- Opponent of Chamberlain's appeasement of the Axis Powers
- Opponent of change
- Opponent of change in policy
- Opponent of Chiang Kai-shek
- Opponent of DDE
- Opponent of DDE
- Opponent of Deep Blue, IBM's chess computer
- Opponent of George and Bill
- Opponent of good
- Opponent of government
- Opponent of Hannibal
- Opponent of Ike
- Opponent of Jackson
- Opponent of Jimmy and Arthur
- Opponent of Kit Carson
- Opponent of Lee
- Opponent of Luther
- Opponent of Luther during the Protestant Reformation
- Opponent of Lyndon
- Opponent of management, at times
- Opponent of Muhammad: 1978
- Opponent of Napoleon
- Opponent of Pericles
- Opponent of Pericles
- Opponent of prevalent doctrine
- Opponent of progress
- Opponent of RE Lee
- Opponent of S Grant
- Opponent of Stalin
- Opponent of stripes in billiards
- Opponent of the CAN-SPAM act
- Opponent of the matador
- Opponent of the O's in the "Beltway Series"
- Opponent of the Patriot Act, for short
- Opponent of the Sadducees
- Opponent of Tom and Harry in 1948
- Opponent of U S Grant
- Opponent of US Grant
- Opponent of Ulysses S Grant
- Opponent of us
- Opponent of Wade
- Opponent of war
- Opponent of Yanks
- Opponent's call
- Opponent's observation
- Opponent's shout
- Opponent's utterance
- Opponent's vote
- Opponent
- Opponents
- Opponents for Perry Mason, for short
- Opponents in a duel
- Opponents in custody cases
- Opponents of "shirts"
- Opponents of "us"
- Opponents of 'us'
- Opponents of 1 Across
- Opponents of 25-Across
- Opponents of a particular policy
- Opponents of defense lawyers: Abbr
- Opponents of Dems
- Opponents of dualism
- Opponents of Hunkers, 1840–50
- Opponents of Reps
- Opponents of standpatters
- Opponents of the '60s-'70s New Left
- Opponents of the 18th Amendment
- Opponents of the GOP