sacred cow 
noun
An idea, custom, or institution held to be above criticism (with reference to the Hindus' respect for the cow as a holy animal): the sacred cow of monetarism the British diet remains a sacred cow...
- It has consistently tackled the sacred cows of sex, religion and politics with wit, irony and hard criticism leaving behind carcasses of exposed folly and evil.
- The idea of paying bloggers is a controversial one, as it challenges some of the sacred cows of the journalistic publishing business.
- We need constructive criticism of our most sacred cows.
- childbed
- child benefit
- child-bereft
- child bird
- childbirth
- child-bride
- childcare
- childcarer
- child-centred
- child-crowing
- child development
- child-directed speech
- Childe
- childed
- child endowment
- childe parte
- Childermas
- Childers, Erskine
- child-farming
- child-free
- child-friendliness
- child-friendly
- child-geared
- child genius
- child guidance