hidden
adj.adj. kept out of sight so that people cannot see or find it easily. You use this to describe things that are secret or covered up.
adj. kept out of sight; concealed from view or discovery. Often functions as a past-participial adjective derived from 'hide'.
The children found a hidden room in the old house.
The hikers discovered a hidden waterfall deep within the forest that was not marked on any map.
The journalist spent months investigating the hidden costs of the infrastructure project, eventually revealing millions in unaccounted expenditures.
Morphologically hid + -en.
Often used as a participial adjective before a noun or after a linking verb.
The key was hided under the mat.The key was hidden under the mat.The past participle of 'hide' is 'hidden', not 'hided'.