From en.wiktionary.org:
[Dumm]
** German
*** Etymology
From [de], from [de], from [de], from [de], from [de].
The modern consonantism is Central and Low German (compare [de], [gml], from
[de]). The rare literary variant [de] is a poetic archaism directly borrowed
from Middle High German; the expected form of this source is early modern
German [de] (now obsolete).
*** Pronunciation
- [de]
- [de]
- [de]
- [de]
*** Adjective
[comp:^]
1. dumb , stupid
**** Declension
[comp:^]
**** Related terms
- [de]
- [de]
- [de]
- [de]
- [de]
*** Further reading
- [R:de:DWDS]
- [R:de:UniLeipzig]
- [R:de:Duden]
** German Low German
*** Alternative forms
- [nds-de]
- [nds-de]
*** Etymology
From [nds-de], from [nds-de], from [nds-de], from [nds-de], from [nds-de].
Compare [de] and [de], [nl], [en], [fy], [da].
*** Pronunciation
- [nds-de]
*** Adjective
[nds-de]
1. dumb , silent , mute
2. dumb , stupid
**** Declension
[head=dumm]
**** Related terms
- [nds-de]