1A person who grinds or sharpens razor blades. Now chiefly historical.
2Any of various birds having a call or song likened to the sound of a cut-throat razor being sharpened; specifically (a) Australian the restless flycatcher, Myiagra inquieta; (b) English regional the European nightjar, Caprimulgus europaeus; (c) English regional the grasshopper warbler, Locustella naevia.
Early 18th century. From razor + grinder.