A political party or movement opposed to the party or government in power.
The difference of quantity or quality between two propositions having the same subject and predicate.
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.
An opposite or contrasting position.
A position in which the player on the move must yield with his king allowing his opponent to advance with his own king.
An unrecognized political party in a one-party state.
A recognized political party or group of parties in multiparty political systems that is present in Parliament or some other legislative body and does not control the floor (usually due to being in the minority).
Actions by one political group against another political group, either by using governmental power or by popular actions such as protests; generally, disagreement in politics.