Opposition means impediment, obstacle. is the act of oppose or oppose something, that is, of put yourself against a situation. It is to object to any fact. To be an opponent is to be antagonistic.
In the legal area, opposition is the intervention of third parties in a third party's process and will be a third party until it intervenes in the demand, because by intervening it becomes part of the process.
in rhetoric (art of good speech) opposition is the argumentation that consists in bringing together two ideas or two expressions that seem antagonistic, that are in opposition.
The adjective "no matter" means that which causes embarrassment or impediment. "Nevertheless" or "notwithstanding" has the same meaning as the conjunctive phrases (however, despite of that), or the prepositional phrase (although), where it expresses only opposition, without causing off-side.
in astronomy, opposition is the relative situation of two or more celestial bodies when their lengths differ 180° from each other.
opposition in politics
In politics, the opposition is the political party that opposes the government, the one that objects, that fights the government's measures.
In a democracy, the right to opposition is an essential element, it is the free expression of thought, it is the right to freedom of opinion.