master is the feminine plural indefinite of mast.

mastN

Kven

mastoN; mastaN

Norwegian Bokmål – Kvendict-nob-fkv/src/N_nobfkv.xml:47852Edit on GitHub Suggest

stivliN

Norsk-nordsamisk ordbokdict-nob-sme/src/N_nobsme.xml:231819Edit on GitHub Suggest

Case	Sg	Pl
Indef	mast	master
Def	masten / masta	mastene