From a primary phebomai (to be put in fear); alarm or fright -- be afraid, + exceedingly, fear, terror.
1. fear, dread, terror; in a subjective sense (οὐδέν ἐστι φόβος εἰ μή προδοσία τῶν ἀπό λογισμοῦ βοηθημάτων, Wis. 17:11; προσδοκίαν λέγω κακοῦ τοῦτο, εἴτε φόβον, εἴτε δέος καλεῖτε, Plato, Protag., p. 358 d.): universally, 1 John 4:18; φόβος ἐπί τινα πίπτει (Acts 19:17 L Tr); Revelation 11:11 Rec.; ἐπιπίπτει, Luke 1:12; Acts 19:17 (R G T WH; Revelation 11:11 L T Tr WH); ἐγένετο, Luke 1:65; Acts 5:5, 11; λαμβάνει τινα, Luke 7:16 (Homer Iliad 11, 402); γίνεται τίνι, Acts 2:43; πλησθῆναι φοβοῦ, Luke 5:26; συνέχεσθαι φόβῳ, Luke 8:37; ἔχειν φόβον, 1 Timothy 5:20 (Herodotus 8, 12); κατεργάζεσθαι; τίνι φόβον, 2 Corinthians 7:11; φοβεῖσθαι φόβον (see φοβέω, 2), Mark 9:41; Luke 2:9; with a genitive of the object added, 1 Peter 3:14 (so Winer's Grammar, § 32, 2; others subject. genitive); ἀπό φοβοῦ, for fear, Luke 21:26; ἀπό τοῦ φοβοῦ, for the fear, with which they were struck, Matthew 14:26; with a genitive of the object added, Matthew 28:4; εἰς φόβον, unto (that ye may) fear, Romans 8:15; μετά φοβοῦ, Matthew 28:8; with καί τρόμου added, 2 Corinthians 7:15; Ephesians 6:5; Philippians 2:12; ἐν φόβῳ καί ἐν τρόμῳ (see τρόμος), 1 Corinthians 2:3; τινα ἐν φόβῳ σῴζειν (Rec.), ἐλεαν (L T Tr WH), with anxious heed lest ye be defiled by the wickedness of those whom ye are rescuing, Jude 1:23; plural φόβοι, feelings of fear, fears (Winer's Grammar, 176 (166)), 2 Corinthians 7:5; φόβος τίνος, genitive of the object (our fear of one): τῶν Ἰουδαίων, John 7:13; John 19:38; John 20:19; βασανισμοῦ, Revelation 18:10, 15; θανάτου, Hebrews 2:15 (Xenophon, mem. l, 4, 7). In an objective sense, that which strikes terror: φόβος ἀγαθῶν ἔργων, or more correctly (with L T Tr WH) τῷ ἀγαθῷ ἔργῳ, a terror to (or for), Romans 13:3.
2. reverence, respect (for authority, rank, dignity): Romans 13:7; 1 Peter 2:18; 1 Peter 3:16 (15); ἡ ἐν φόβῳ ἀναστροφή, behavior coupled with (cf. ἐν, I. 5 e.) reverence for one's husband, 1 Peter 3:2; φόβος with a genitive of the object: τοῦ κυρίου, Acts 9:31; 2 Corinthians 5:11; Χριστοῦ, Ephesians 5:21 (not Rec.); Θεοῦ, Romans 3:18; 2 Corinthians 7:1; (Ephesians 5:21 Rec.); Θεοῦ is omitted as suggested by the context, 1 Peter 1:17; (often in the O. T. יְהוָה יִרְאַת and אֱלֹהִים יִרְאַת). (Synonyms: see δειλία, δέος, at the end; cf. φοβέω.)