Plattdeutsch
Concise Oxford English Dictionary © 2008 Oxford University Press:
Plattdeutsch /ˈplatdɔɪtʃ/
▶noun & adjective another term for Low German.
– origin Ger., from Du. Platduits, from plat ‘flat, low’ + Duits ‘German’.
'Plattdeutsch' also found in these Oxford entries:

