From Wiktionary, the free dictionary
Fasten n (strong, genitive Fastens, no plural)
- fasting
Declension of Fasten [sg-only, neuter, strong]
- “Fasten” in Digitales Wörterbuch der deutschen Sprache
- “Fasten” in Uni Leipzig: Wortschatz-Lexikon
- “Fasten” in Duden online