Brother

The Hebrew word is used in various senses in the Old Testament, as,

Any kinsman, and not a mere brother; e.g. nephew, (Genesis 13:8; 14:16) husband, (Solomon 4:9)

One of the same tribe. (2 Samuel 19:13)

Of the same people, (Exodus 2:11) or even of a cognate people. (Numbers 20:14)

An ally. (Amos 1:9)

Any friend, (Job 5:15)

One of the same office. (1 Kings 9:13)

A fellow man. (Leviticus 19:17)

Metaphorically of any similarity, as in (Job 30:19) The word adelphos has a similar range of meanings in the New Testament.