c.1300, "crime of stealing what is consecrated to God," from Old French sacrilege (12c.), from Latin sacrilegium "temple robbery," from sacrilegus "stealer of sacred things," from phrase sacrum legere "to steal sacred things," from sacrum "sacred object (from neuter singular of sacer "sacred;" see sacred) + legere "take, pick up" (see lecture (n.)). Second element is not from religion. Transferred sense of "profanation of anything held sacred" is attested from late 14c.