clean sheet

:  free from dirt or pollution

:  free from contamination or disease

:  free or relatively free from radioactivity

:  so as to clean

:  in a clean manner

:  all the way :  completely

:  to make clean: such as

:  to rid of dirt, impurities, or extraneous matter

:  to rid of corruption

:  an act of cleaning dirt especially from the surface of something

:  a broad piece of cloth

:  bedsheet

:  sail

:  rolled or spread out in a sheet

:  of, relating to, or concerned with the making of sheet metal

:  to cover with a sheet

:  to furnish with sheets

:  to form into sheets

:  a rope or chain that regulates the angle at which a sail is set in relation to the wind

:  the spaces at either end of an open boat not occupied by thwarts :  foresheets and stern sheets together

:  to move or set (a sail) by manipulation of a sheet