(1) Original or primitive. (2) First in importance.
Example:
She argued that to restore the economy, the primal necessity was to reform the health care system.
We might speak of the primal innocence of youth, or of the primal intensity of someone's devotion to a cause. Certain psychologists employ "primal scream" therapy, in which patients relive painful experiences from their past and express their frustration and anger through screaming and even violence.