Definitions of ruin:

• noun:   a ruined building

  Example: "They explored several Roman ruins"

• noun:   an event that results in destruction
• noun:   an irrecoverable state of devastation and destruction

  Example: "You have brought ruin on this entire family"

• noun:   destruction achieved by wrecking something
• noun:   failure that results in a loss of position or reputation
• noun:   the process of becoming dilapidated
• verb:   destroy or cause to fail

  Example: "This behavior will ruin your chances of winning the election"

• verb:   fall into ruin
• verb:   reduce to ruins

  Example: "The country lay ruined after the war"

• verb:   reduce to bankruptcy
• verb:   deprive of virginity
• verb:   destroy completely; damage irreparably

  Example: "You have ruined my car by pouring sugar in the tank!"