Impressor is a term which can be used to refer to a printer or a printing press. There are a few synonyms which can substitute for this term when required. One such synonym is "printing machine", which is a general term and can be used to describe any type of machine for printing texts or images. Another synonym for impressor is "printing press", which specifically refers to a mechanical device that applies pressure to inked surfaces to reproduce text or images. A third synonym for impressor is "pressman", which refers to the person who operates the printing press. These terms can be interchangeable in certain contexts where reference to a printer or printing machine is required.