Dependency has a number of meanings:

• In project management, a dependency is a link amongst a project's terminal elements.
• In computer science, dependency is a state in which one object uses a functionality of another object. This may cause changes on implementation of one object that can affect implementation of another object.
• In behavioural medicine , dependence describes a continuum of physical and psychological attachments related to the concept of addiction.
• Dependency theory is an economic worldview.
• A dependent area is a classification of territory.
• The Ross Dependency is an area of Antarctica claimed by New Zealand.
• Co-dependency is a behavioural condition.
• A chemical dependency is such a strong need for a substance that it becomes necessary to have this substance just to function properly.