Strong's #251: 'ach (pronounced awkh)
 a primitive word; a brother (used in the widest sense of literal relationship and metaphorical affinity or resemblance (like 1)):--another, brother(-ly); kindred, like, other. Compare also the proper names beginning with "Ah-" or "Ahi-".
Brown-Driver-Briggs Hebrew Lexicon:
 
  'âch 
 
 1) brother
 
 1a) brother of same parents
 1b) half-brother (same father)
 1c) relative, kinship, same tribe
 1d) each to the other (reciprocal relationship)
 1e) (figuratively) of resemblance
 
  Part of Speech: noun masculine
Relation: a primitive word
Usage:
This word is used 629 times:
Genesis 27:45: "Until  thy brother's anger from thee, and he forget that which"
Genesis 28:2: "from thence of the daughters of Laban thy mother's  brother."
Genesis 28:5: "son of Bethuel the Syrian,  the brother of Rebekah, Jacob's and Esau's mother."
Genesis 29:4: "And Jacob said  unto them, My brethren, be ye? And they said, Of Haran"
Genesis 29:10: "the daughter of Laban his mother's  brother, and the sheep of Laban his mother's brother,"
Genesis 29:10: "and the sheep of Laban his mother's  brother, that Jacob went near, and rolled"
Genesis 29:10: "the flock of Laban his mother's  brother."
Genesis 29:12: "he was her father's  brother, and that he was Rebekah's son:"
Genesis 29:15: "unto Jacob, thou  art my brother, shouldest thou therefore serve me for naught? tell me, what"
Genesis 31:23: "And he took  his brethren him, and pursued after him seven days'"
Genesis 31:25: "in the mount: and Laban with  his brethren pitched in the mount of Gilead."
Genesis 31:32: "let him not live: before  our brethren discern thou what is thine with me, and take"
Genesis 31:37: "stuff? set it here before  my brethren and thy brethren, that they may judge between"
Genesis 31:37: "set it here before my brethren  and thy brethren, that they may judge between us both."
Genesis 31:46: "And Jacob said  unto his brethren, stones; and they took stones, and made"
Genesis 31:54: "sacrifice and called  his brethren to eat bread: and they did eat bread,"
Genesis 32:3: "him to Esau  his brother unto the land of Seir, the country of Edom."
Genesis 32:6: "saying, We came to  thy brother Esau, and also he cometh to meet"
Genesis 32:11: "Deliver me, I pray thee, from the hand  of my brother, from the hand of Esau:"
Genesis 32:13: "to his hand a present for Esau  his brother;"
Genesis 32:17: "When Esau  my brother meeteth thee, and asketh thee, saying, Whose"
Genesis 33:3: "until he came near to  his brother."
Genesis 33:9: "said, I have  my brother; keep that"
Genesis 34:11: "unto and unto  her brethren, Let me find grace in your eyes, and what"
Genesis 34:25: "Simeon and Levi, Dinah's  brethren, took each man his sword, and came"
Genesis 35:1: "thee when thou fleddest from the face of Esau  thy brother."
Genesis 35:7: "unto him, when he fled from the face  of his brother."
Genesis 36:6: "into the country from the face  of his brother Jacob."
Genesis 37:2: "was feeding the flock with  his brethren; and the lad was with the sons"
Genesis 37:4: " And when his brethren saw that loved him more than all his brethren,"
Genesis 37:4: "loved him more than all  his brethren, they hated him, and could not"
Genesis 37:5: "dreamed a dream,  it his brethren: and they hated him yet the more."
Genesis 37:8: " And his brethren said to him, Shalt thou indeed reign us? or shalt thou indeed have dominion"
Genesis 37:9: "another and told  it his brethren, and said, Behold, I have dreamed a dream"
Genesis 37:10: "it to his father,  his brethren: and his father rebuked him, and said unto him, What"
Genesis 37:10: "thou hast dreamed? Shall I and thy mother  and thy brethren indeed come to bow down ourselves to thee to the earth?"
Genesis 37:11: " And his brethren envied him; but his father the saying."
Genesis 37:12: " And his brethren went to feed their father's flock in Shechem."
Genesis 37:13: "unto Do not  thy brethren feed the flock in Shechem? come, and I will send"
Genesis 37:14: "whether it be well  with thy brethren, and well with the flocks; and bring me word"
Genesis 37:16: "I seek  my brethren: tell me, I pray thee, where they"
Genesis 37:17: "to Dothan. And Joseph went after  his brethren, and found them in Dothan."
Genesis 37:19: "And they said one to  another, Behold, this dreamer"
Genesis 37:23: "Joseph unto  his brethren, that they stripped Joseph out of"
Genesis 37:26: "And Judah said unto  his brethren, What profit is it if we slay"
Genesis 37:26: "is it if we slay  our brother, and conceal his blood?"
Genesis 37:27: "be upon him; for he  is our brother and our flesh. And his brethren were content."
Genesis 37:27: "he is our brother and our flesh.  And his brethren were content."
Genesis 37:30: "And he returned unto  his brethren, The child is not; and I, whither"
Genesis 38:1: "went down from  his brethren, and turned in to a certain"