Paul describes the 'unfruitful works of darkness' that believers should not participate in, adding 'for it is shameful even to speak of the things that they do in secret' (Ephesians 5:12). The adverb emphasizes concealment and hiddenness—actions done out of sight because they cannot bear scrutiny. Classical usage describes secret actions, whether conspiratorial or simply private. Paul's point is that darkness-deeds require secrecy because they are shameful; merely naming them in public is disgraceful.