- OPPONENT
- Rival
- Venus to Serena, in eleven tournament finals
- Adlai Stevenson, to 44 Down
- Frazier, to Ali
- Yankees, to the Red Sox
- Adversary
- Other side
- Antagonist
- Foe
- Ali, to Frazier at Manila
- Tilden, to Hayes
- The house, to a blackjack player
- Schmeling, to Louis
- Spinks, to 41-Across, twice
- Counter person
- One from the other side