Any contradiction or paradox.
In the thought of the German philosopher Immanuel Kant (1724–1804): an apparent contradiction between valid conclusions; a paradox.
An opposite or contrasting position.
The difference of quantity or quality between two propositions having the same subject and predicate.
A political party or movement opposed to the party or government in power.
In United States intellectual property law, a proceeding in which an interested party seeks to prevent the registration of a trademark or patent.
The action of opposing or of being in conflict.
The apparent relative position of two celestial bodies when one is at an angle of 180 degrees from the other as seen from the Earth.
A position in which the player on the move must yield with his king allowing his opponent to advance with his own king.