Leak

A leak is a way (usually an opening) for fluid to escape a container or fluid-containing system, such as a tank or a ship's hull, through which the contents of the container can escape or outside matter can enter the container. Leaks are usually unintended and therefore undesired. The word ''leak'' usually refers to a gradual loss; a sudden loss is usually called a ''spill''.

The matter leaking in or out can be gas, liquid, a highly viscous paste, or even a solid such as a powdered or granular solid or other solid particles. Provided by Wikipedia