re·gime / riˈzhēm; rā-/ (also ré·gime) • n. 1. a government, esp. an authoritarian one.2. a system or planned way of doing things, esp. one imposed from above: detention centers with a very tough physical regime. ∎  a coordinated program for the promotion or restoration of health; a regimen: a low-calorie, low-fat regime. ∎  the conditions under which a scientific or industrial process occurs.

régime †regimen of health; system of government. XVIII. — F. — L. regimen, f. regere rule.
So regimen regulation of matters pert. to health XIV; rule, government XV; (gram.) government XVI. — L. regiment †rule, government; †control, management; †place under a certain rule XIV; †regimen of health; body of troops forming a unit XVI. — (O)F. régiment — late L. regimentum rule; see -MENT. Hence regiment vb. XVII, regimental adj. and sb. pl. (-AL1) XVIII.