A state of internal activity of an organism that is a necessary condition before a given stimulus will elicit a class of responses; e.g., a certain level of hunger (drive) must be present before food will elicit an eating response.
Basic urge, instinct, motivation; a term used to avoid confusion with the more purely biological concept of instinct.
A condition or state of the individual that activates or directs behavior, hunger, thirst, etc, are powerful motivational forces.
Natural force that compels a person to an action as the hunger drive directs one to eat. The basic drives are sex, hunger, and thirst. A secondary drive is a learned or acquired drive, not directly related to satisfying a physical need (e.g., a striving for recognition).