sanddynene is the feminine plural definite of sanddyne.

sanddyneN

Kven

hietadyyniN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:25289Edit on GitHub Suggest

Case	Sg	Pl
Indef	sanddyne	sanddyner
Def	sanddynen / sanddyna	sanddynene