Greek word · G3392

μιαίνω

miainō

to stain

Miainō means "to stain, make ritually impure, defile." In the Greek Old Testament it regularly renders Hebrew ṭāmēʾ, the purity vocabulary of Leviticus and Ezekiel. Impurity is not the same as moral wrongdoing, though the two can overlap.

Appears 5 times in 4 verses of the Greek New Testament. · Updated October 23, 2026

What it means

μιαίνω

[in LXX chiefly for טָמֵא ;]

1. to dye or stain.

2. to stain, defile, soil;

(a) in physical sense;

(b) in moral sense : Titus 1:15, Hebrews 12:15, Jude 1:8;

(with) in ritual sense (cf. Leviticus 22:5, al.): John 18:28.†

SYN.: μολύνω, to besmear, which also differs from μ. in that it is never used, as μ. in its primary meaning, in an honourable sense (cf. Tr., Syn., § xxxi) (AS)

From G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), via STEPBible.org (CC BY 4.0).

In depth

From the study of 1 Enoch 12:4

Range of meaning: Miainō means "to stain, make ritually impure, defile." In the Greek Old Testament it regularly renders Hebrew ṭāmēʾ, the purity vocabulary of Leviticus and Ezekiel. Impurity is not the same as moral wrongdoing, though the two can overlap. It is a state that bars contact with the holy and must be kept apart from the sanctuary.
Against the English: "Defiled themselves" can sound like vague moral disgust, or as if sex or women were dirty in themselves. The original is a technical purity category: holy beings have crossed a boundary that should never be crossed.
How it drifted: In modern English "defile" has become a loose moral or emotional word, so the ritual and boundary logic of the original goes unheard.
Used elsewhere in the period: Lev 18:20, 24 ("you shall not defile yourself" through forbidden unions); Lev 21:1–15 (priests must not defile themselves and must marry only suitable wives); Ezek 44:22–25. 1 Enoch 15:3–4 spells out the logic: "You were holy, spiritual, living forever, and you defiled yourselves with the blood of women... and begot children with the blood of flesh." 1 Enoch 10:11 calls the act defiling "in all their uncleanness."

From the study of Hebrews 12:15

Range of meaning: To stain, pollute, make ritually or morally impure.
Against the English: 'Defile' is accurate, but modern readers hear vague moral contamination. The word belongs to the world of purity and holiness: becoming unfit to approach a holy God.
How it drifted: Most modern readers no longer think in purity categories, so 'defile' loses its link to worship and access to God.
Used elsewhere in the period: Often in the LXX for making unclean the sanctuary, the land or people (e.g. Leviticus 11:44; 18:24–28; Numbers 35:34). In the NT: John 18:28 (the priests avoiding defilement before Passover), Titus 1:15, Jude 8. Hebrews 13:4 uses the related adjective amiantos, 'undefiled' (marriage bed).

From the study of John 18:28

Range of meaning: To stain or soil, and from there to pollute or defile. It is used of ritual impurity (the Greek Old Testament's main word for the Hebrew tame', 'become unclean') and also of moral corruption.
Against the English: 'Defiled' is accurate, but to modern ears it sounds like moral dirt or sin. NIV's 'ceremonial uncleanness' captures the ritual sense.
How it drifted: In modern English 'defile' is mostly a moral or sexual word. The ritual purity system behind it is unfamiliar to most readers.
Used elsewhere in the period: Greek Old Testament: Lev 11:44; 18:24; Num 19:13, 20 (a person with corpse impurity who does not purify himself 'defiles' the sanctuary); Num 9:6–7, where men made unclean by a corpse could not keep the Passover. In the New Testament the moral sense appears at Titus 1:15, Heb 12:15 and Jude 8.

Where it appears

John · 1

John 18:28 μιανθῶσιν they may be defiled

Then they led Jesus away from Caiaphas into the Praetorium. By now it was early morning, and the Jews did not enter the Praetorium, to avoid being defiled and unable to eat the Passover.

Here: 'Become ritually impure'. This is the Greek Old Testament's word for the purity laws' 'unclean' state, which shut a person out of sacred meals and the temple. It describes a ritual status, not a moral failing.

Titus · 2

Titus 1:15 μεμιαμμένοις μεμίανται defiled, have been defiled

To the pure, all things are pure; but to the defiled and unbelieving, nothing is pure. Indeed, both their minds and their consciences are defiled.

Here: Perfect participle: 'those who have been defiled and remain so'. This is the technical purity word for becoming unclean. It is turned against the very people who were most anxious about defilement.

Hebrews · 1

Hebrews 12:15 μιανθῶσιν may be defiled

See to it that no one falls short of the grace of God, and that no root of bitterness springs up to cause trouble and defile many.

Here: 'Be defiled.' This is impurity language: becoming unfit to come near a holy God. It is the direct opposite of the 'holiness' that v.14 tells them to pursue.

Jude · 1

Jude 1:8 μιαίνουσιν, defile,

Yet in the same way these dreamers defile their bodies, reject authority, and slander glorious beings.

Here: Present tense: an ongoing practice. It is purity language, making something unclean. In Jewish writings it is the word used for the fallen angels who 'defiled themselves' with women (1 Enoch), which v. 6 has just recalled.

Word data: STEPBible.org (CC BY 4.0), main text only.