Definition of "Opposition" :
noun: the action of opposing something that you disapprove or disagree with
"Despite opposition from the newspapers he went ahead."
noun: the act of hostile groups opposing each other
"The invaders encountered stiff opposition."
noun: a body of people united in opposing something
noun: the major political party opposed to the party in office and prepared to replace it if elected
"Her Majesty's loyal opposition."
noun: an armed adversary (especially a member of an opposing military force)
noun: a contestant that you are matched against
noun: a direction opposite to another
noun: the relation between opposed entities