The act of calling into question or challenging the accuracy or propriety of something.
A demonstration in a court of law, or before another finder of fact, that a witness was ingenuine before, and is therefore less likely to tell the truth now.
An accusation that a person has committed a crime against the state, such as treason.
The act of impeaching or charging a public official with misconduct, especially if serious, often with the aim of having the official dismissed from office.
The state of being impeached.
The action of opposing or of being in conflict.
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 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.