One's master, employer, or lord — the principal owner or person in charge of a house, estate, or household.
この家の主は高齢の男性だと聞いた。
I heard that the master (owner) of this house is an elderly man.
雇い主にお願いして休みを取った。
I asked my employer for time off.
城の主が住民に挨拶した。
The lord of the castle greeted the inhabitants.
Leader or head of a country, group, or organization; the chief or principal person in charge.
党の主が政策の方向を示した。
The party leader indicated the direction of policy.
地域の主として住民の信頼を集めている。
As the head of the area, he has gained the residents' trust.
In Christianity, 'Lord' — referring to God or Jesus Christ.
祈りの中で『主よ、導きをください』と言った。
In prayer I said, 'Lord, please give guidance.'
The main thing; the chief or principal item, consideration, or purpose.
会議の主な目的は次年度の予算を決めることだ。
The main purpose of the meeting is to decide next year's budget.
主な理由を三つ挙げて説明した。
I explained by listing three main reasons.