[1] : The Collaborative International Dictionary of English v.0.48

brother \broth"er\ bru^th"~er, n.; pl. brothers
   bru^th"~erz or brethren bre^th"re^n. see
   brethren. oe. brother, as. br=oethor; akin to os.
   brothar, d. broeder, ohg. pruodar, g. bruder, icel.
   br=oethir, sw.  dan. broder, goth. br=othornar, ir.
   brathair, w. brawd, pl. brodyr, lith. brolis, lett. brahlis,
   russ. brat', pol.  serv. brat, oslav. bratru^, l. frater,
   skr. bhr=at.r, zend bratar brother, gr. fra`thr, fra`twr,
   a clansman. the common plural is brothers; in the solemn
   style, brethren, oe. pl. brether, bretheren, as. dative
   sing. br=eether, nom. pl. br=oethor, br=oethru.
   root258. cf. friar, fraternal.
   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.
         1913 webster +pjc

               two of us in the churchyard lie,
               my sister and my brother.          --wordsworth.
         1913 webster

   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." --shak.
      1913 webster

            we few, we happy few, we band of brothers,
            for he to-day that sheds his blood with me
            shall be my brother.                  --shak.
      1913 webster

   3. one who, or that which, resembles another in distinctive
      qualities or traits of character.
      1913 webster

            he also that is slothful in his work is brother to
            him that is a great waster.           --prov. xviii.
                                                  9.
      1913 webster

            that april morn
            of this the very brother.             --wordsworth.
      1913 webster

   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.
         1913 webster

               for of whom such massacre
               make they but of their brethren, men of men?
                                                  --milton.
         1913 webster

   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.
      1913 webster
see also:
brothers brethren friar fraternal half brother brother of the half blood 
uterine brother agnate brother consanguine brother brother-german full brother 
sister sibling brother jonathan blood brother blood 

[2] : The Collaborative International Dictionary of English v.0.48

brother \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. --sir w. scott.
   1913 webster
see also:
brothered 

[3] : WordNet (r) 2.0

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
see also:
blood brother sister buddy chum crony pal 
sidekick comrade brethren 

[4] : Moby Thesaurus II by Grady Ward, 1.0

198 moby thesaurus words for "brother":
   greek, abbacomes, abbot, acquaintance, adjunct, advocate,
   affiliate, ally, alter ego, analogon, analogue, ascetic, associate,
   aunt, auntie, backer, beadsman, bedfellow, belonger, best friend,
   blood brother, bosom friend, brethren, brother-in-arms, bub, bubba,
   bud, buddy, caloyer, card-carrier, card-carrying member,
   cardholder, casual acquaintance, catechumen, celibate, cenobite,
   charter member, chum, church member, churchman, churchwoman,
   close acquaintance, close copy, close friend, close match, clubber,
   clubman, clubwoman, coadjutor, cognate, cohort, colleague,
   committeeman, communicant, companion, compatriot, compeer,
   complement, comrade, confederate, confidant, confidante, confrere,
   congenator, congener, consociate, consort, conventioneer,
   conventioner, conventionist, conventual, conventual prior,
   coordinate, correlate, correlative, correspondent, counterpart,
   country cousin, cousin, cousin once removed, cousin twice removed,
   crony, daughter, dues-paying member, enlistee, enrollee,
   equivalent, familiar, father, favorer, fellow, fellow creature,
   fellow member, fellowman, first cousin, foster brother, frater,
   fraternity man, friar, friend, grand prior, grandnephew,
   grandniece, granduncle, great-aunt, great-uncle, guildsman,
   half brother, hermit, hieromonach, honorary member, image,
   initiate, inseparable friend, insider, intimate, joiner,
   kid brother, kin, kindred spirit, kinsman, laic, lay abbot,
   lay brother, lay sister, layman, laywoman, life member, like,
   likeness, lover, mate, member, mendicant, monastic, monk, mother,
   near duplicate, neighbor, nephew, niece, nuncle, nunks, nunky,
   obverse, one of us, other self, pal, palmer, parallel, parishioner,
   partisan, pendant, pickup, picture, pilgrim, pillar saint,
   pillarist, pledge, prior, reciprocal, relation, relative,
   religieux, religious, repository, second cousin, second self,
   secular, sibling, similitude, simulacrum, sis, sissy, sister,
   sister-german, sistern, socius, son, sorority girl, sorority woman,
   soul mate, stepbrother, stepsister, stylite, such, suchlike,
   supporter, sympathizer, tally, the like of, the likes of, twin,
   unc, uncle, uncs, uterine brother, well-wisher

[5] : Easton's 1897 Bible Dictionary

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.
   

[6] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

brother, domest. relat. he who is born from the same father and mother with 
another, or from one of them only. 
     2. brothers are of the whole blood, when they are born of the same 
father and mother, and of the half blood, when they are the issue of one of 
them only. 
     3. in the civil law, when they are the children of the same father and 
mother, they are called brothers germain; when they descend from the same 
father, but not the same mother, they are consanguine brothers; when they 
are the issue of the same mother, but not the same father, they are uterine 
brothers. a half brother, is one who is born of the same father or mother, 
but not of both. one born of the same parents before they were married, a 
left-sided brother; and a bastard born of the same father or mother, is 
called a natural brother. vide blood; half-blood; line; and merl. repert. 
mot frere; dict. de jurisp. mot frere; code, 3, 28, 27 nov. 84, praef; 
dane's ab. index, h. t. 

Brother >> B Words
Brother, definition of term: Brother
brother_pag1.html

Foster Brother >> F Words
Foster Brother, definition of term: Foster Brother
foster+brother_pag1.html

Blood Brother >> B Words
Blood Brother, definition of term: Blood Brother
blood+brother_pag1.html

Big Brother >> B Words
Big Brother, definition of term: Big Brother
big+brother_pag1.html