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.