【Sacred】 ,  【sacrosanct】 ,  【inviolate】 ,  【inviolable】  can all mean having such a character as to be protected by law, custom, tradition, or human respect against breach, intrusion, defilement, or profanation.

【Sacred】  (see also HOLY ) implies either a setting apart for a special and often exclusive use or end or a special character or quality which makes the person or thing held 【sacred】 an object of almost religious veneration or reverence.

【Sacrosanct】 , which in technical religious use implies the utmost of holiness or sacredness, in its more general use may retain this implication, but often tends to suggest an imputed rather than a genuinely possessed character justifying freedom from attack or violation; its emphasis in such use is usually somewhat ironical and occasionally slightly derisive.

【Inviolate】  and  【inviolable】  apply to things (as laws, principles, treaties, agreements, institutions, persons, places, or objects) that for one reason or another are secure from breach, infringement, attack, intrusion, or injury; the terms differ from each other chiefly in that  【inviolate】  suggests the fact of not having been violated while  【inviolable】  implies a character which does not permit or which distinctly forbids violation; thus, one holds a vow  【inviolable】  but keeps his vow  【inviolate】 .