Hard Explained

Hard or Hardness may refer to:

• Hardness, resistance of physical materials to change under force.
• Hard water has a high mineral content.
• Mathematical difficulty; see computational complexity theory.
• A difficulty level in a video game.
• Street hardness, an attribute characterized by physical and mental toughness due to living in hostile urban environments.
• Hard, Austria, a town in Austria.
• Slang for erection of the penis when sexually excited or aroused. See Erection