used as a term of address for those male persons engaged in the same movement; "Greetings, comrade!"
In the latter case he is more definitely called a half brother, or brother of the half blood
1 A baptized male member of the congregation 2 All baptized Christians are brothers scripturally speaking, regardless of sex, in the same way that the word mankind covers the entire human race, females included (Compare 1Pe 2: 17 ) The Insight book [it] says
You can describe a man as your brother if he belongs to the same race, religion, country, profession, or trade union as you, or if he has similar ideas to you. He told reporters he'd come to be with his Latvian brothers
A man who is a member of a religious order, but is not ordained or studying for the priesthood
Brother is a title given to a man who belongs to a religious community such as a monastery. Brother Otto. the Christian Brothers community which owns the castle