Greek word · G4203

πορνεύω

porneuō

to sin sexually

To engage in porneia, meaning any sexual relations outside what Jewish law allowed: prostitution, adultery, incest, and so on. It is broader than 'fornication' between unmarried people.

Appears 8 times in 7 verses of the Greek New Testament. · Updated October 31, 2026

What it means

πορνεύω

[in LXX for זָנָה ;]

1. to prostitute the body for hire.

2. to commit fornication: Mark 10:19 (WH, mg), 1 Corinthians 6:18 10:8, Revelation 2:14, 20. Metaphorical (as in LXX: 1 Chronicles 5:25, Jeremiah 3:6, Hosea 9:1, al.), of idolatry (but see Swete, Ap., 180 f.), Revelation 17:2 18:3, 9 (cf. ἐκ- πορνεύω).†

(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 Revelation 2:20

Range of meaning: To engage in porneia, meaning any sexual relations outside what Jewish law allowed: prostitution, adultery, incest, and so on. It is broader than 'fornication' between unmarried people. In the Septuagint (the Greek Old Testament) it also translates Hebrew zanah, the prophets' image for Israel being unfaithful to God by going after other gods (Hosea 1–3; Jeremiah 3; Ezekiel 16, 23).
Against the English: KJV 'commit fornication' narrows it to sex between unmarried people in modern ears. 'Sexual immorality' (BSB, WEB, NIV, ESV) keeps the sexual breadth but loses the idolatry overtone. YLT's 'commit whoredom' keeps the prophetic harlotry image.
How it drifted: 'Fornication' narrowed in later English to unmarried sex, while porneia covers far more ground.
Used elsewhere in the period: Septuagint Hosea 4:12; Ezekiel 16:15–34 (harlotry meaning idolatry). Numbers 25:1–2, where Israel 'played the harlot' with Moab and ate their sacrifices, is the Balaam story behind Revelation 2:14. Acts 15:20, 29 lists 'idol-offerings' and 'porneia' together in the apostles' decree. In Revelation, Babylon the harlot commits porneia with the kings of the earth (17:2; 18:3), which is plainly political and religious, not only sexual.

From the study of 1 Corinthians 10:8

Range of meaning: From pornē ('prostitute'). In classical Greek it first meant to work as a prostitute or to use one. In Jewish Greek (the Septuagint and later) it grew into a general word for any sexual intercourse outside what God's law allowed: prostitution, adultery, incest, sex with outsiders that pulled Israelites toward other gods. In the prophets it was also a common picture of Israel's unfaithfulness to God by worshipping idols (Hosea, Jeremiah, Ezekiel).
Against the English: KJV 'fornication' sounds to many modern readers like sex between unmarried people, a narrower and more technical idea than the Greek. Modern 'commit sexual immorality' (BSB, NIV, WEB) is closer in range but vague. YLT 'commit whoredom' keeps the prostitution root but sounds as if only prostitution is meant.
How it drifted: English 'fornication' (from Latin fornix, an arch or vault, where prostitutes worked in Rome) gradually narrowed, especially in modern moral and legal usage, to sex between unmarried people. The Greek word never had that narrow technical sense.
Used elsewhere in the period: Septuagint Numbers 25:1: 'the people began to commit sexual sin (ekporneusai) with the daughters of Moab,' which Numbers 25:2 links directly to eating their sacrifices and bowing to their gods. Paul uses the same word group in 1 Cor 5:1 (a man living with his father's wife), 6:13–18 (sex with a prostitute), and 7:2. Revelation 2:14, 20 joins 'eating food sacrificed to idols and committing porneia', also recalling Balaam and Peor. Jewish writers of the period (e.g. Philo, Life of Moses 1.295–305) retell Peor as seduction into idolatry through sex and feasting.

From the study of Revelation 2:14

Range of meaning: To engage in porneia: any sexual intercourse outside what the law allowed, including prostitution, adultery, incest and other forbidden unions. Following the Hebrew prophets, who called Israel's worship of other gods 'whoring' (zānâ), it is also a standard image for religious unfaithfulness.
Against the English: KJV 'commit fornication' now sounds to most readers like 'sex between unmarried people' specifically. YLT 'commit whoredom' keeps the prophetic image but sounds crude. 'Commit sexual immorality' (BSB, WEB, ESV, NIV) is broad enough for the literal sense, though English readers will not hear the idolatry image in it.
How it drifted: The Latin fornicari (Vulgate) gave English 'fornication'. Later moral and legal usage narrowed that word to sex between unmarried people, which is narrower than the Greek.
Used elsewhere in the period: In the Septuagint, ekporneuō and porneuō translate zānâ in Numbers 25:1 ('the people began to commit whoredom with the daughters of Moab'). The same verb family is used for idolatry in Hosea 1–4, Jeremiah 3 and Ezekiel 16 and 23. In Revelation, 'porneia' and 'commit porneia' describe Babylon's dealings with the kings and nations (14:8; 17:2; 18:3, 9), which is clearly figurative, and 'Jezebel' at Thyatira (2:20–21).

Where it appears

1 Corinthians · 3

1 Corinthians 6:18 πορνεύων sinning sexually

Flee from sexual immorality. Every other sin a man can commit is outside his body, but he who sins sexually sins against his own body.

Here: 'The one engaging in porneia'. The present participle describes someone doing it, possibly as an ongoing practice, like the man who 'joins himself to a prostitute' in 6:16.
1 Corinthians 10:8 πορνεύωμεν ἐπόρνευσαν, shall we commit sexual immorality, committed sexual immorality,

We should not commit sexual immorality, as some of them did, and in one day twenty-three thousand of them died.

Here: 'Let us not be doing porneia.' The form is a present-tense 'let us' that describes an ongoing practice, not a one-off slip. Paul uses 'we' and counts himself in, after the 'you' of v. 7.

Revelation · 5

Revelation 2:14 πορνεῦσαι. to commit sexual immorality.

But I have a few things against you, because some of you hold to the teaching of Balaam, who taught Balak to place a stumbling block before the Israelites so they would eat food sacrificed to idols and commit sexual immorality.

Here: To engage in illicit sexual activity. Following the prophets, it is also an image for being unfaithful to God. At Peor the two went together, and here it may mean the literal act, the image, or both (see debates).
Revelation 2:20 πορνεῦσαι to commit sexual immorality

But I have this against you: You tolerate that woman Jezebel, who calls herself a prophetess. By her teaching she misleads My servants to be sexually immoral and to eat food sacrificed to idols.

Here: Illicit sexual activity, and in the prophetic tradition also unfaithfulness to God through idolatry. Here it may mean either one, or both.
Revelation 17:2 ἐπόρνευσαν committed sexual immorality

The kings of the earth were immoral with her, and those who dwell on the earth were intoxicated with the wine of her immorality.”

Here: 'They went whoring.' The past tense sums up the whole relationship as a finished fact. In the prophets' picture-language this means rulers selling their loyalty to a seductive power in return for wealth and security: political alliance, trade, and the worship tied to them. The sexual image is meant to shock.
Revelation 18:3 ἐπόρνευσαν, committed sexual immorality,

All the nations have drunk the wine of the passion of her immorality. The kings of the earth were immoral with her, and the merchants of the earth have grown wealthy from the extravagance of her luxury.”

Here: A simple past (aorist) verb that sums up their conduct as a completed whole. For the kings, 'whoring with' Babylon means alliances of power, shared idolatry and profit.
Revelation 18:9 πορνεύσαντες having committed sexual immorality

Then the kings of the earth who committed sexual immorality and lived in luxury with her will weep and wail at the sight of the smoke rising from the fire that consumes her.

Here: A past-tense participle: 'having prostituted themselves'. This is the prophets' image of a harlot city. It stands for a profitable alliance, both political and commercial, that also drew the kings into the city's gods and imperial worship (17:2; 18:3).

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