in opposition to; contrary to; adverse or hostile to: twenty votes against ten; against reason.
in resistance to or defense from: protection against burglars.
in an opposite direction to: to ride against the wind.
into contact or collision with; toward; upon: The rain beat against the window.
in contact with: to lean against the wall.
in preparation for; in provision for: money saved against a rainy day.
having as background: a design of flowers against a dark wall.
in exchange for; as a balance to or debit or charge on: He asked for an advance against his salary.