This adjective describes what is unclear, hidden, or uncertain—not evident to sight or knowledge. In Luke 11:44, Jesus condemns the Pharisees as being like unmarked graves: people walk over them unaware of the defilement beneath. In 1 Corinthians 14:8, Paul argues that if the trumpet gives an unclear sound, who will prepare for battle? The word emphasizes lack of clarity—what is hidden from view, obscured from knowledge, or uncertain in signal. It's the opposite of manifest, denoting what fails to communicate clearly or remains concealed from observation.