trelasta is the feminine singular definite of trelast.

trelastN

Kven

puulastiN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:95732Edit on GitHub Suggest

sahádoaibmaN

Norsk-nordsamisk ordbokdict-nob-sme/src/N_nobsme.xml:170964Edit on GitHub Suggest

Case	Sg	Pl
Indef	trelast	trelaster
Def	trelasten / trelasta	trelastene