Original Word: ἁγιάζω
Part of Speech: Verb
Phonetic Spelling: (hag-ee-ad’-zo)
Short Definition: I make holy, sanctify
Definition: I make holy, treat as holy, set apart as holy, sanctify, hallow, purify.
Thayer teaches us that sancification is
to purify internally by reformation of soul: John 17:17, 19(through knowledge of the truth, cf. John 8:32); 1 Thessalonians 5:23; 1 Corinthians 1:2 (ἐν Χριστῷ Ἰησοῦ in the fellowship of Christ, the Holy One); Romans 15:16 (ἐν πνεύματι ἁγίῳimbued with the Holy Spirit, the divine source of holiness); Jude 1:1 (L T Tr WH ἠγαπημένοις (which see)); Revelation 22:11. In general, Christians are called ἡγιασμένοι (cf. Deuteronomy 33:3), as those who, freed from the impurity of wickedness, have been brought near to God by their faith and sanctity, Acts 20:32; Acts 26:18. In 1 Corinthians 7:14ἁγιάζεσθαι is used in a peculiar sense of those who, although not Christians themselves, are yet, by marriage with a Christian, withdrawn from the contamination of heathen impiety and brought under the saving influence of the Holy Spirit displaying itself among Christians; cf. Neander at the passage.
For additional study, see http://biblehub.com