dumheter is the masculine plural indefinite of dumhet.

dumhetN

Kven

tyhmyysN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:71778Edit on GitHub Suggest

jallodatN

Norsk-nordsamisk ordbokdict-nob-sme/src/N_nobsme.xml:57624Edit on GitHub Suggest

Case	Sg	Pl
Indef	dumhet	dumheter
Def	dumheten	dumhetene