Fetching details from the dictionary...

head (of a household); proprietor (of a store); proprietress; landlord; landlady; master (of a servant)
「主人」 has another reading with different meanings.
主人は毎朝早く起きて運動している。
My husband gets up early every morning and exercises.
旅館の主人が玄関で出迎えてくれた。
The inn owner greeted us at the entrance.
主人の帰りを待ちながら夕飯を準備した。
I prepared dinner while waiting for my husband to return.