Concealed means deliberately hidden from view. A concealed entrance, concealed lighting, concealed from her.
The deliberateness is essential: something concealed was hidden on purpose, where something hidden may simply be out of sight. Concealed entrance is a standard road sign. In law, concealing evidence is an offence in itself. Note concealment; and that in design, concealed lighting and concealed fixings are praised for exactly the quality the word usually condemns.
1adjectiveconcealedDeliberately hidden from view.
“A concealed camera in the smoke alarm filmed the thief.”
concealed is a state of being hidden.