ἅγιος, -α, ον (< τό ἅγός, religious awe; ἅζω, to venerate), [in LXX chiefly for קֹ֫דֶשׁ ;] primarily, dedicated to the gods, sacred (Hdt.; rare in Att., never in Hom., Hes. and Trag., who use ἁγνός), hence, holy, characteristic of God, separated to God, worthy of veneration. __1. Its highest application is to God himself, in his purity, majesty, and glory: Refs Luk.1:49, Jhn.17:11, Rev.4:8. Hence __(a) of things and places which have a claim to reverence as sacred to God, e.g. the Temple: Refs Mat.24:15, Heb.9:1; __(b) of persons employed by him, as angels: 1Th.3:13; prophets, Luk.1:70; apostles, Eph.3:5. __2. Applied to persons as separated to God's service: __(a) of Christ, Refs Mrk.1:24, Jhn.6:69, Act.4:30; __(b) of Christians, Refs Act.9:13, Rom.1:7, Heb.6:10, Rev.5:8. __3. In the moral sense of sharing God's purity: Refs Mrk.6:20, Jhn.17:11, Act.3:14, Rev.3:7. __4. Of pure, clean sacrifices and offerings: Refs 1Co.7:14, Eph.1:4. SYN.: 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 opp. to nefas), that which is based on everlasting ordinances of right. (Cf. Tr., Syn., §lxxxviii; DB, ii, 399 f.; Cremer, 34, 594-601; MM, VGT, see word) (AS)
Thayer:
1) reverend, worthy of veneration 1a) of things which on account of some connection with God possess a certain distinction and claim to reverence, as places sacred to God which are not to be profaned 1b) of persons whose services God employs, for example, apostles 2) set apart for God, to be as it were, exclusively his 3) services and offerings 3a) prepared for God with solemn rite, pure, clean 4) in a moral sense, pure sinless upright holy
ἅγιον
hagion
hag'-ee-on
Neuter of G40; a sacred thing (that is, spot)
G37 ἁγιάζωἁγιάζω
hagiazō
hag-ee-ad'-zo
From G40; to makeholy, that is, (ceremonially) purify or consecrate; (mentally) to venerate
KJV Usage: hallow, be holy, sanctify.
G41 ἁγιότηςἁγιότης
hagiotēs
hag-ee-ot'-ace
From G40; sanctity (that is, properly the state)
KJV Usage: holiness.
G42 ἁγιωσύνηἁγιωσύνη
hagiōsunē
hag-ee-o-soo'-nay
From G40; sacredness (that is, properly the quality)
KJV Usage: holiness.
G53 ἁγνόςἁγνός
hagnos
hag-nos'
From the same as G40; properly clean, that is, (figuratively) innocent, modest, perfect
KJV Usage: chaste, clean, pure.
G3741 ὅσιοςὅσιος
hosios
hos'-ee-os
Of uncertain affinity; properly right (by intrinsic or divine character; thus distinguished from G1342, which refers rather to human statutes and relations; from G2413, which denotes formal consecration; and from G40, which relates to purity from defilement), that is, hallowed (pious, sacred, sure)
G5878Synonyms for Holy, Sacred, Pure.
See Definition for ieros { [G2411]}
See Definition for osios { [G3741]}
See Definition for agios { [G40]}
See Definition for agnos { [G53]}
See Definition for semnos { [G4586]}
None of these words in classical Greek has necessarily any moral
significance. Those which now have such a meaning have developed it in
Biblical Greek.
ieros means sacred, implying some special relation to God, so
that it may not be violated. It refers, however, to formal relation
rather than to character. It designates an external relation, which
ordinarily is not an internal relation as well. It is used to describe
persons or things. This is the commonest word for holy in
classical Greek, and expresses their usual conception of holiness, but
it is rare in the N.T. because it fails to express the fullness of the
N.T. conception.
osios, used of persons or things, describes that which is in
harmony with the divine constitution of the moral universe. Hence, it
is that which is in accordance with the general and instinctively felt
idea of right, "what is consecrated and sanctioned by universal law
and consent" (Passow), rather than what is in accordance with any
system of revealed truth. As contrary to osios, i.e., as
anosia, the Greeks regarded, e.g., a marriage between brother
and sister such as was common in Egypt, or the omission of the rites
of sepulture in connection with a relative. agios has probably as
its fundamental meaning separation, i.e., from the world to God's
service. If not the original meaning, this at any rate is a meaning
early in use. This separation, however, is not chiefly external, it is
rather a separation from evil and defilement. The moral signification
of the word is therefore the prominent one. This word, rare and of
neutral meaning in classical Greek, has been developed in meaning, so
that it expresses the full N.T. conception of holiness as no other
does.
agnos is probably related to agios. It means specifically
pure. But this may be only in a ceremonial sense, or it may have
a moral signification. It sometimes describes freedom from
impurities of the flesh.