The -ard here refers to the overabundace of regional channels: HR, WDR, SWR, NDR, BR, RBB, MDR, etc. pp.

Ah yes, in English it apparently means ‘-ly’, in German it means ‘Arbeitsgemeinschaft der öffentlich-rechtlichen Rundfunkanstalten der Bundesrepublik Deutschland’… I guess some languages are just more expressive than others.