To return to a former or less developed state. After making some progress, the patient began to regress and needed additional therapy.
To analyze the relationship between variables using regression analysis; to model statistically. The researcher regressed exam scores on study hours and attendance.
Of a celestial body or its orbital node, to move backward in its apparent path; to undergo retrograde motion. The lunar nodes regress westward along the ecliptic over an 18-year cycle.