This weekend I finally managed to read last September’s edition of the “Wendish news”.  In the research section I read the correspondence between Mr. Zwar and two gentlemen from Germany about the different meanings of the terms wend / wendish / windish.  I would like to add something:

I think the “Sorbisches Kulturlexikon” published by the Serbski Insitut gives a good definition of the term “wendish”:

1. In the wider sense it applies to the [general] language of the western Slavonic tribes, settling in the region of the Baltic sea, nowadays East Germany, but also in the Alpine area (then referring to the later Slovenes as “windish”).
2. In a narrower sense it applies to the Sorbian Wends, such as Lower Lusatian Sorbs and Upper Lusatian Sorbs.

That means, that looking at the widespread areas in medieval Germany where Wendish-speaking parishes / settlements could still be found, outside the Sorbian settlement area, they were still Wendish, but not exactly Sorbian.

Concerning the word “windish”, it is mostly used to refer to Slovenes, but in the former versions of the written German, it was sometimes also used for their northern brothers/cousins.  (The famous Slovenian reformer Primus Truber referred to the Biblical translations he co-edited as made for these peasants, who speak Windish, but lack knowledge of German.  The elite would speak an Austrian style German, though.)

I think the best way to put it would be to say that, “Wends” is the term for these Western Slavs, who did not have their own state-like territory; and in a narrower sense, it refers to the Lusatian Sorbs. (But this is just an individual view).

Best regards, 
Martin Brützke/ Měrćin Brycka
Sorbian Museum