A solvent is a substance in which another substance, usually a solute, is dissolved. A solvent is usually a liquid; however, it may be a liquid, solid or gas in which another can be dissolved. The term is in common usage in chemistry.
The solvent is the dissolving agent in a solution. The substance that is dissolved is the solute. The most versatile solvent known is water.
When you hear the word 'solvent,' you should automatically think of a substance that 'breaks down' another substance. For example, turpentine (paint thinner) and nail polish remover are both solvents. You can find more information here: http://en.wikipedia.org/wiki/Solvent