From hagios; to make holy, i.e. (ceremonially) purify or consecrate; (mentally) to venerate -- hallow, be holy, sanctify.

see GREEK hagios

1. to render or acknowledge to be venerable, to hallow: τό ὄνομα τοῦ Θεοῦ, Matthew 6:9 (so of God, Isaiah 29:23; Ezekiel 20:41; Ezekiel 38:23; Sir. 33:4 (Sir. 36:4)); (Luke 11:2); τόν Χριστόν, 1 Peter 3:15 (R G Θεόν). Since the stamp of sacredness passes over from the holiness of God to whatever has any connection with God, ἁγιάζειν denotes

2. to separate from things profane and dedicate to God, to consecrate and so render inviolable;

a. things (πᾶν πρωτότοκον, τά ἀρσενικά, Deuteronomy 15:19; ἡμέραν, Exodus 20:8; οἶκον, 2 Chronicles 7:16, etc.): τόν χρυσόν, Matthew 23:17; τό δῶρον, Matthew 23:19; σκεῦος, 2 Timothy 2:21.

b. persons. So Christ is said by undergoing death to consecrate himself to God, whose will he in that way fulfills, John 17:19; God is said ἁγιάσαι Christ, i. e. to have selected him for his service (cf. ἀφορίζειν, Galatians 1:15) by having committed to him the office of Messiah, John 10:36, cf. Jeremiah 1:5; Sir. 36:12 (ἐξ αὐτῶν ἡγίασε, καί πρός αὐτόν ἤγγισεν, of his selection of men for the priesthood); Sir. 45:4 Sir. 49:7. Since only what is pure and without blemish can be devoted and offered to God (Leviticus 22:20; Deuteronomy 15:21; Deuteronomy 17:1), ἁγιάζω signifies

3. to purify (ἀπό τῶν ἀκαθαρσιῶν is added in Leviticus 16:19; 2 Samuel 11:4); and

a. to cleanse externally (πρός τήν τῆς σαρκός καθαρότητα), to purify levitically: Hebrews 9:13; 1 Timothy 4:5.

b. to purify by expiation, free from the guilt of sin: 1 Corinthians 6:11; Ephesians 5:26; Hebrews 10:10, 14, 29; Hebrews 13:12; Hebrews 2:11 (equivalent to כִּפֶר, Exodus 29:33, 36); cf. Pfleiderer, Paulinismus, p. 340ff (English translation 2:68f).

c. 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 ἁγίῳ imbued 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 7:14 ἁγιάζεσθαι 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.