sacrosanct
adjective uk/ˈsæk.rə.sæŋkt/ us/ˈsæk.rə.sæŋkt/
神圣不容更改（或侵犯）的
thought to be too important or too special to be changed
I'm willing to help on any weekday, but my weekends are sacrosanct. 我乐意在任何一个工作日帮忙，不过周末可不容侵占的。
Synonyms: inviolable inviolate