lasset is the neuter singular definite of lass.

lassN

Kven

kuormaN; lastiN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:40021Edit on GitHub Suggest

guorbmiN

Norsk-nordsamisk ordbokdict-nob-sme/src/N_nobsme.xml:68711Edit on GitHub Suggest

Case	Sg	Pl
Indef	lass	lass
Def	lasset	lassa