opposition

Etymology

From Middle English opposicioun, from Old French oposicion (whence French opposition), from Late Latin oppositiō, translating Ancient Greek ἀντίθεσις (antíthesis), from the past participle stem of classical Latin oppōnō (“I set against”).

noun

1. The action of opposing or of being in conflict.
   The two politicians are in opposition.
   Terra Firma is an Alliance political party formed after the First Contact War. Its policy agenda is based on the principle that Earth must 'stand firm' against alien influences. This covers a variety of legislation. Recent activities by Terra Firma include opposition to a law requiring high school alien language study, a proposal to increase tariffs on alien imports, and leading a popular movement to mark the First Contact War with a public holiday. 2008, BioWare, Mass Effect, Redwood City: Electronic Arts, →OCLC, PC, scene: Terra Firma Party Codex entry
   That worries the government, which fears that environmental activism could become the foundation for more general political opposition. 2013-08-10, “Can China clean up fast enough?”, in The Economist, volume 408, number 8848
2. An opposite or contrasting position.
3. (astronomy) 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.
4. (politics) A political party or movement opposed to the party or government in power.
   leader of the opposition
5. (law) In United States intellectual property law, a proceeding in which an interested party seeks to prevent the registration of a trademark or patent.
6. (chess) A position in which the player on the move must yield with his king allowing his opponent to advance with his own king.
7. (logic) The difference of quantity or quality between two propositions having the same subject and predicate.