Taboo

Taboo, prohibition against an item, person, or type of behaviour. In religious taboos, the forbidden item is believed to be either unclean or sacred, and the taboo is imposed for protection against the item's power. Prohibitions against incest and marriage within certain groups are examples of behavioural taboos. Some taboos are not wholly a matter of religion, but are rather more concerned with social relationships; an example is the observance of caste. Common taboo areas (as far as acknowledgement of them goes) include death, divorce, and mental illness.