An Etymological Dictionary of the German Language/Annotated/Borke
Borke, feminine, ‘bark,’ a Low German loan-word, which is not found in Upper German. The proper High German is Rinde. Compare Low German barke, English and Danish bark, Old Icelandic bǫrkr, ‘bark’; Gothic *barkus is not recorded. Its connection with bergen (in the sense of ‘concealing’) may be possible as far as its form is concerned; but on account of Sanscrit bhûrja, masculine ‘birch,’ neuter ‘birch-bark,’ its relation to Birke is more probable.