Middle voice from parrhesia; to be frank in utterance, or confident in spirit and demeanor -- be (wax) bold, (preach, speak) boldly.
see GREEK parrhesia
1. to use freedom in speaking, be free-spoken; to speak freely ((A. V. boldly)): Acts 18:26; Acts 19:8; ἐν τῷ ὀνόματι τοῦ Ἰησοῦ, relying on the name of Jesus, Acts 9:27, 28(29); also ἐπί τῷ κυρίῳ, Acts 14:3.
2. to grow confident, have boldness, show assurance, assume a bold bearing: εἶπεν, Acts 13:46 (R. V. spake out boldly); λαλεῖν, Acts 26:26; παρρησιάζεσθαι ἐν τίνι, in reliance on one to take courage, followed by an infinitive of the thing to be done: λαλῆσαι, Ephesians 6:20; 1 Thessalonians 2:2. (Xenophon, Demosthenes, Aeschines, Polybius, Philo, Plutarch, others; the Sept.; Sir. 6:11.)