Drive: A need state energized by stimulus deprivation (no food), stimulus apprehension (thinking about male or female protuberances), or dread (forgeting one's anniversary) that gets you going, but doesn't tell you where. When coupled with cognition, ignites something called behavior (e.g., raiding the refigerator, flirting, making excuses to wife), and when defined as combined becomes undefined, such as consciousness, free will, and 'about last night'.
