broth·er /ˈbrʌðɚ/
  兄弟
  brother
  兄弟
  brother
  兄弟 同級
  Broth·er v. t. [imp. & p. p. Brothered ] To make a brother of; to call or treat as a brother; to admit to a brotherhood.
  ◄ ►
  Broth·er n.; pl. Brothers or Brethren See Brethren.
  1. A male person who has the same father and mother with another person, or who has one of them only. In the latter case he is more definitely called a half brother, or brother of the half blood.
  Note: A brother having the same mother but different fathers is called a uterine brother, and one having the same father but a different mother is called an agnate brother, or in Law  a consanguine brother.  A brother having the same father and mother is called a brother-german or full brother.  The same modifying terms are applied to sister or sibling.
  Two of us in the churchyard lie,
  My sister and my brother.   --Wordsworth.
  2. One related or closely united to another by some common tie or interest, as of rank, profession, membership in a society, toil, suffering, etc.; -- used among judges, clergymen, monks, physicians, lawyers, professors of religion, etc. “A brother of your order.”
  We few, we happy few, we band of brothers,
  For he to-day that sheds his blood with me
  Shall be my brother.   --Shak.
  3. One who, or that which, resembles another in distinctive qualities or traits of character.
     He also that is slothful in his work is brother to him that is a great waster.   --Prov. xviii. 9.
  That April morn
  Of this the very brother.   --Wordsworth.
  Note: ☞ In Scripture, the term brother is applied to a kinsman by blood more remote than a son of the same parents, as in the case of Abraham and Lot, Jacob and Laban. In a more general sense, brother or brethren is used for fellow-man or fellow-men.
  For of whom such massacre
  Make they but of their brethren, men of men?   --Milton.
  Brother Jonathan, a humorous designation for the people of the United States collectively.  The phrase is said to have originated from Washington's referring to the patriotic Jonathan Trumbull, governor of Connecticut, as “Brother Jonathan.”
  Blood brother. See under Blood.
  brother
       n 1: a male with the same parents as someone else; "my brother
            still lives with our parents" [syn: blood brother]
            [ant: sister]
       2: a male person who is a fellow member (of a fraternity or
          religion of other group); "none of his brothers would
          betray him"
       3: a close friend who accompanies his buddies in their
          activities [syn: buddy, chum, crony, pal, sidekick]
       4: used as a term of address for those male persons engaged in
          the same movement; "Greetings, comrade!" [syn: comrade]
       5: (Roman Catholic Church) a title given to a monk and used as
          form of address; "a Benedictine Brother"
       [also: brethren (pl)]
  Brother
     (1.) In the natural and common sense (Matt. 1:2; Luke 3:1, 19).
       (2.) A near relation, a cousin (Gen. 13:8; 14:16; Matt. 12:46;
     John 7:3; Acts 1:14; Gal. 1:19).
       (3.) Simply a fellow-countryman (Matt. 5:47; Acts 3:22; Heb.
     7:5).
       (4.) A disciple or follower (Matt. 25:40; Heb. 2:11, 12).
       (5.) One of the same faith (Amos 1:9; Acts 9:30; 11:29; 1 Cor.
     5:11); whence the early disciples of our Lord were known to each
     other as brethren.
       (6.) A colleague in office (Ezra 3:2; 1 Cor. 1:1; 2 Cor. 1:1).
       (7.) A fellow-man (Gen. 9:5; 19:7; Matt. 5:22, 23, 24; 7:5;
     Heb. 2:17).
       (8.) One beloved or closely united with another in affection
     (2 Sam. 1:26; Acts 6:3; 1 Thess. 5:1). Brethren of Jesus (Matt.
     1:25; 12:46, 50: Mark 3:31, 32; Gal. 1:19; 1 Cor. 9:5, etc.)
     were probably the younger children of Joseph and Mary. Some have
     supposed that they may have been the children of Joseph by a
     former marriage, and others that they were the children of Mary,
     the Virgin's sister, and wife of Cleophas. The first
     interpretation, however, is the most natural.