(especially of a principle, place, or routine) regarded as too important or valuable to be interfered with.
Late 15th century: from Latin sacrosanctus, from sacro ‘by a sacred rite’ (ablative of sacrum) + sanctus ‘holy’.
“A woman’s rights to her own body are sacrosanct.”
“Democracy is sacrosanct and nothing should interfere.”
With regard to, or at the level of, orders in a taxonomic system; according to an ordinal number, system, etc.; on an ordinal scale; with regard to order.
Mid 19th century; earliest use found in The Edinburgh Review. From ordinal + -ly.