'Brother's' in the Bible

Then the Lord said to Cain, “Where is Abel your brother?” And he [lied and] said, “I do not know. Am I my brother’s keeper?”

The Lord said, “What have you done? The voice of your brother’s [innocent] blood is crying out to Me from the ground [for justice].

And now you are cursed from the ground, which has opened its mouth to receive your brother’s [shed] blood from your hand.

His brother’s name was Jubal; he became the father of all those [musicians] who play the lyre and flute.

Two sons were born to Eber; the name of one was Peleg (division), for [the inhabitants of] the earth were divided in his days; and his brother’s name was Joktan.

Abram took Sarai his wife and Lot his nephew, and all their possessions which they had acquired, and the people (servants) which they had acquired in Haran, and they set out to go to the land of Canaan. When they came to the land of Canaan,

And they also took [captive] Lot, Abram’s nephew, and his possessions and left, for he was living in Sodom.

And I bowed down my head and worshiped the Lord, and blessed the Lord, the God of my master Abraham, who had led me in the right way to take the daughter of my master’s brother to his son [as a wife].

Stay with him for a while, until your brother’s anger subsides.

When your brother’s anger toward you subsides and he forgets what you did to him, then I will send and bring you back from there. Why should I be deprived of you both in a single day?”

Then Judah told Onan, “Go in to your brother’s widow, and perform your duty as a brother-in-law [under the levirate marriage custom]; [be her husband and] raise children for [the name of] your brother.”

Onan knew that the child (heir) would not be his [but his dead brother’s]; so whenever he lay with his brother’s widow, he spilled his seed on the ground [to prevent conception], so that he would not give a child to his brother.