hidden as in not accessible to view

• "concealed (or hidden) damage"
• "in stormy weather the stars are out of sight"

Synonyms

• concealednot accessible to view; hidden on any grounds for any motive
• out of sightnot accessible to view; no longer visible; quietly in concealment

hidden as in designed to elude detection

• "a hidden room or place of concealment such as a priest hole"
• "a secret passage"
• "the secret compartment in the desk"

Synonyms

• secretsomething that should remain hidden from others (especially information that is not to be passed on); information known only to a special group; something that baffles understanding and cannot be explained; not open or public; conducted with or marked by hidden aims or methods; not openly made known; communicated covertly; not expressed; designed to elude detection; hidden from general view or use; (of information) given in confidence or in secret; indulging only covertly; having an import not apparent to the senses nor obvious to the intelligence; the next to highest level of official classification for documents

hidden as in difficult to find

• "hidden valleys"
• "a hidden cave"
• "an obscure retreat"

Synonyms

• obscuremake less visible or unclear; make unclear, indistinct, or blurred; make obscure or unclear; reduce a vowel to a neutral one, such as a schwa ; make undecipherable or imperceptible by obscuring or concealing; not clearly expressed or understood; marked by difficulty of style or expression; difficult to find; not famous or acclaimed; not drawing attention; remote and separate physically or socially