late 14c., seintefie "to consecrate," from O.Fr. saintifier (12c.), from L.L. sanctificare "to make holy," from sanctus "holy" (see saint) + root of facere "to make" (see factitious). Form altered to conform with Latin. Meaning "to render holy
or legitimate by religious sanction" is from c.1400; transfered sense of "to render worthy of respect" is from c.1600.