sacrosanct (adj.) Look up sacrosanct at Dictionary.com
c.1600, from Latin sacrosanctus "protected by religious sanction," from sacro, ablative of sacrum "religious sanction" (from neuter singular of sacer "sacred") + sanctus, past participle of sancire "make sacred" (see sacred). Earlier in partially anglicized form sacro-seint (c.1500).