From Wiktionary, the free dictionary
Ultimately from Latin December. Cognates include West Frisian desimber.
deetsember m
- (Föhr-Amrum) December
- Months of the year in Föhr-Amrum Frisian: janewoore, febrewoore, marts, april, mei, jüüne, jüüle, august, september, oktuuber, nofember, deetsember