Word Origin & History
c.1300, from pp. of obsolete verb sacren "to make holy" (early 13c.), from O.Fr. sacrer (12c.), from L. sacrare "to make sacred, consecrate," from sacer (gen. sacri) "sacred, dedicated, holy, accursed," from O.L. saceres, which Tucker connects to base *saq- "bind, restrict, enclose, protect," explaining
that "words for both 'oath' & 'curse' are regularly words of 'binding.' " But Buck merely groups it with Oscan sakrim, Umbrian sacra and calls it "a distinctive Italic group, without any clear outside connections." Nasalized form is sancire "make sacred, confirm, ratify, ordain." Sacred cow "object of Hindu veneration," is from 1891; figurative sense is first recorded 1910, from Western views of Hinduism.