„Or, a fess wavy azure accompanied from two fleur-de-lis sable above and one beneath.“ 
The arms were granted on January 4, 1939. The three fleur-de-lis on gold are derived from the old arms of the Lords von Gimbte, who probably originated from the area and who became extinct in the 16th century. The fess wavy symbolises the Ems river.
This image is taken from www.ngw.nl – Heraldry of the World –  an international civic heraldry site by Ralf Hartemink. http://www.ngw.nl/int/dld/g/gimbte.htm

Grevener Wappenkunde
unknown - constructed and added by Jürgen Krause