1. verbal adjective (from אָמַן to prop; Niph. to be firm), firm, metaphorically, faithful: ὁ ἀμήν, Rev. iii. 14 (where is added ὁ μάρτυς ὁ πιστός καί ἀληθινός).

2. it came to be used as an adverb by which something is asserted or confirmed:

a. at the beginning of a discourse, surely, of a truth, truly; so frequent in the discourses of Christ in Matthew, Mark, and Luke: ἀμήν λέγω ὑμῖν 'I solemnly declare unto you,' e. g. Matthew 5:18; Mark 3:28; Luke 4:24. The repetition of the word (ἀμήν ἀμήν), employed by John alone in his Gospel (twenty-five times), has the force of a superlative, most assuredly: John 1:51 (); .

b. at the close of a sentence; so it is, so be it, may it be fulfilled (γένοιτο, the Sept. Numbers 5:22; Deuteronomy 27:15, etc.): Romans 1:25; Romans 9:5; Galatians 1:5; Ephesians 3:21; Philippians 4:20; 1 Timothy 1:17; Hebrews 13:21; 1 Peter 4:11; Revelation 1:6, and often; cf. Jeremiah 11:5; Jeremiah 35:6 (); 1 Kings 1:30. It was a custom, which passed over from the synagogues into the Christian assemblies, that when he who had read or discoursed had offered up a solemn prayer to God, the others in attendance responded Amen, and thus made the substance of what was uttered their own: 1 Corinthians 14:16 (τό ἀμήν, the well-known response Amen), cf. Numbers 5:22; Deuteronomy 27:15ff; Nehemiah 5:13; Nehemiah 8:6. 2 Corinthians 1:20 αἱ ἐπαγγελίαι ... τό ναί, καί ... τό ἀμήν, i. e. had shown themselves most sure. (Cf. B. D. under the word .)