BIR means "one" .  ER means "man; soldier; hero; husband" .  *** 2.    The name CHAUHANS: http://en.wikipedia.org/wiki/Chauhan "Chohan , Chohhan , Chauhan or Chouhan ( Punjabi : ਚੌਹਾਨ, Hindi : चौहान) - A              gotra   (lineage) found among the Jats , [ 2 ] Rajputs