underdraw

1. (transitive) To cover or line the underside of (a floor or roof) with plasterwork, boarding or other such treatment.Examples: "The [roof] had never been underdrawn, its entire anatomy lay bare to an inquiring eye, except where a frame of wood laden with oatcakes, and clusters of legs of beef, mutton and ham, concealed it."; "He has the whole of the room underdrawn, with the exception of two bays at one end; he admits plenty of air by the windows in the roof into the triangular shaped space formed by the roof and the underdrawing;"transitive

2. (transitive) To represent inadequately in an artistic depiction, or in words.transitive