The word sanctification refers to the act of making holy or setting apart as special. The word is used five times in the Authorized Version of the New Testament (1 Corinthians 1:30, 1 Thessalonians 4:3,1 Thessalonians 4:4, 2 Thessalonians 2:13, and 1 Peter 1:2).
To sanctify means “to set apart for special use or purpose,” and “to make holy or sacred,” and etymologically from the Latin verb 'sanctificare' which in turn is from sanctus “holy” and facere “to make.”