From Wikipedia, the free encyclopedia
Hard or "hardness" may refer to:
- Hardness, resistance of physical materials to change under force
- Hard water, water with 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
- Hard (Brainpower album), a music album by Brainpower
- Hard (Gang of Four album), an album by Gang of Four
- Hard (Zürich), a quarter in Zürich
- Hard (band), a Hungarian hard rock supergroup
- Hard (Jagged Edge album)
- Hard (tennis), a type of tennis court