Concealed
81hid himself — concealed himself, camouflaged himself …
82hid his secret — concealed his secret …
83hidden hand — concealed hand …
84hidden meaning — concealed intention or purpose, undisclosed significance …
85hidden message — concealed meaning …
86under the cloak of — concealed by, covered by …
87up one's sleeve — concealed, hidden …
88wheels within wheels — concealed motives, hidden motives …
89under cover of — concealed by. ↘while pretending to do something. → send someone to Coventry …
90Oubliette — Concealed dungeon having a trap door in its ceiling as its only opening, where prisoners were often left to starve to death, sometimes in total darkness …