ἅγιοςhágios

primarily, dedicated to the gods, sacred, hence, holy, characteristic of God, separated to God, worthy of veneration.

Greek (New Testament) · G40

Meanings

1. Its highest application is to God himself, in his purity, majesty, and glory: Luke 1:49, John 17:11, Revelation 4:8. Hence

(a) of things and places which have a claim to reverence as sacred to God, e.g. the Temple: Matthew 24:15, Hebrews 9:1

(b) of persons employed by him, as angels: 1 Thessalonians 3:13; prophets, Luke 1:70; apostles, Ephesians 3:5.

2. Applied to persons as separated to God's service

(a) of Christ, Mark 1:24, John 6:69, Acts 4:30

(b) of Christians, Acts 9:13, Romans 1:7, Hebrews 6:10, Revelation 5:8.

3. In the moral sense of sharing God's purity: Mark 6:20, John 17:11, Acts 3:14, Revelation 3:7.

4. Of pure, clean sacrifices and offerings: 1 Corinthians 7:14, Ephesians 1:4.

Synonyms

ἁγνός, pure, both in ceremonial and spiritual sense; ἱερός (sacer), sacred, that which is inviolable because of its (external) relation to God; ὅσιος (sanctus as opposed to nefas), that which is based on everlasting ordinances of right.

Same root

Where it appears

Appears 220 times in the Bible.

Matthew 1:18 This is how Jesus the Messiah was born. His mother, Mary, was engaged to be married to Joseph. But before the marriage took place, while she was still a virgin, she became pregnant through the power of the Holy Spirit.
Matthew 1:20 As he considered this, an angel of the Lord appeared to him in a dream. “Joseph, son of David,” the angel said, “do not be afraid to take Mary as your wife. For the child within her was conceived by the Holy Spirit.
Matthew 3:11 “I baptize with water those who repent of their sins and turn to God. But someone is coming soon who is greater than I am—so much greater that I’m not worthy even to be his slave and carry his sandals. He will baptize you with the Holy Spirit and with fire.
Matthew 4:5 Then the devil took him to the holy city, Jerusalem, to the highest point of the Temple,
Matthew 7:6 “Don’t waste what is holy on people who are unholy. Don’t throw your pearls to pigs! They will trample the pearls, then turn and attack you.
Matthew 12:32 Anyone who speaks against the Son of Man can be forgiven, but anyone who speaks against the Holy Spirit will never be forgiven, either in this world or in the world to come.

See every passage

Matthew 1:18, 1:20, 3:11, 4:5, 7:6, 12:32, 24:15, 27:52, 27:53, 28:19
Mark 1:8, 1:24, 3:29, 6:20, 8:38, 12:36, 13:11
Luke 1:15, 1:35, 1:41, 1:49, 1:67, 1:70, 1:72, 2:23, 2:25, 2:26, 3:16, 3:22, 4:1, 4:34, 9:26, 10:21, 11:13, 12:10, 12:12
John 1:33, 6:69, 14:26, 17:11, 20:22
Acts 1:2, 1:5, 1:8, 1:16, 2:4, 2:33, 2:38, 3:14, 3:21, 4:8, 4:25, 4:27, 4:30, 4:31, 5:3, 5:32, 6:5, 6:13, 7:33, 7:51, 7:55, 8:15, 8:17, 8:19, 9:13, 9:17, 9:31, 9:32, 9:41, 10:22, 10:38, 10:44, 10:45, 10:47, 11:15, 11:16, 11:24, 13:2, 13:4, 13:9, 13:52, 15:8, 15:28, 16:6, 19:2, 19:6, 20:23, 20:28, 21:11, 21:28, 26:10, 28:25
Romans 1:2, 1:7, 5:5, 7:12, 8:27, 9:1, 11:16, 12:1, 12:13, 14:17, 15:13, 15:16, 15:25, 15:26, 15:31, 16:2, 16:15, 16:16
1 Corinthians 1:2, 3:17, 6:1, 6:2, 6:19, 7:14, 7:34, 12:3, 14:33, 16:1, 16:15, 16:20
2 Corinthians 1:1, 6:6, 8:4, 9:1, 9:12, 13:12
Ephesians 1:1, 1:4, 1:13, 1:15, 1:18, 2:19, 2:21, 3:5, 3:8, 3:18, 4:12, 4:30, 5:3, 5:27, 6:18
Philippians 1:1, 4:21, 4:22
Colossians 1:2, 1:4, 1:12, 1:22, 1:26, 3:12
1 Thessalonians 1:5, 1:6, 3:13, 4:8, 5:26
2 Thessalonians 1:10
1 Timothy 5:10
2 Timothy 1:9, 1:14
Titus 3:5
Philemon 1:5, 1:7
Hebrews 2:4, 3:1, 3:7, 6:4, 6:10, 9:8, 10:15, 13:24
1 Peter 1:12, 1:15, 1:16, 2:5, 2:9, 3:5
2 Peter 1:18, 1:21, 2:21, 3:2, 3:11
1 John 2:20
Jude 1:3, 1:14, 1:20
Revelation 3:7, 4:8, 5:8, 6:10, 8:3, 8:4, 11:2, 11:18, 13:7, 13:10, 14:10, 14:12, 16:6, 17:6, 18:20, 18:24, 19:8, 20:6, 20:9, 21:2, 21:10, 22:11, 22:19

Source: G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), public domain.