lie confused, be made mess of

mixed up, muddled, confused, entangled

a scam, scandal

wrangling, quarrelling

to cause confusion, bustle, agitation, alarm

anarchy, disturbance, riot

stomach upset, indigestion

tribal system

immune system

the limbic system, the part of the brain involved in our behavioural and emotional responses

economic system

decimal system

outmoded set-up, system or order

central nervous system

habit, way of life, disposition, custom, practice, conduct

polyandry

(Biology) the natural management of cells

Reproductive system.

system of education or instruction

feudalism, feudal system