'Brethren' in the Bible

There came then his brethren and his mother, and, standing without, sent unto him, calling him.

And the multitude sat about him, and they said unto him, Behold, thy mother and thy brethren without seek for thee.

And he answered them, saying, Who is my mother, or my brethren?

And he looked round about on them which sat about him, and said, Behold my mother and my brethren!

And Jesus answered and said, Verily I say unto you, There is no man that hath left house, or brethren, or sisters, or father, or mother, or wife, or children, or lands, for my sake, and the gospel's,

But he shall receive an hundredfold now in this time, houses, and brethren, and sisters, and mothers, and children, and lands, with persecutions; and in the world to come eternal life.

Now there were seven brethren: and the first took a wife, and dying left no seed.