Merriam-Webster Collegiate Dictionary - sanctify

 transitive verb  (-fied; -fying)  Etymology: Middle English seintefien, sanctifien, from Anglo-French seintefier, sanctifier, from Late Latin sanctificare, from Latin sanctus sacred — more at saint  Date: 14th century  1. to set apart to a sacred purpose or to religious use ; consecrate  2. to free from sin ; purify  3.  a. to impart or impute sacredness, inviolability, or respect to  b. to give moral or social sanction to  4. to make productive of holiness or piety observe the day of the sabbath, to ~ it — Deuteronomy 5:12(Douay Version)