主 is one of the most commonly used Japanese kanji, and it also has a lot of special readings in addition to the standard onyomi and kunyomi readings.
ONYOMI 音読み
ぬし nushi おも omo あるじ aruji
KUNYOMI 訓読み
シュ shu ス su シュウ shuu
Examples
のろいはのろい主に返る。Curses, like chickens, come home to roost.この家のあるじは私だ。It is I who am head of this family.読書が彼のおもな楽しみだ。Reading is his chief amusement.この国の主な産物の1つはコーヒーだ。One of the main products of this country is coffee.昨年の主な出来事は何でしたか。What were the chief events of last year?彼の主な興味は史学にある。His main interest is in history.この計画の主な目的はなんですか。What is the main purpose of this plan?小麦粉はケーキの主な材料だ。Flour is the main ingredient in cakes.軽率さが彼の主な特徴である。Carelessness is his principal feature.君は君自身の運命の主でもあります。You are the master of your own destiny.