Source : Webster's Revised Unabridged Dictionary (1913)

Bawler \Bawl"er\, n.
   One who bawls.

Source : WordNet®

bawler
     n 1: someone who communicates vocally in a very loud voice [syn:
          {roarer}, {bellower}, {screamer}, {screecher}, {shouter},
           {yeller}]
     2: a loud weeper; "their new baby is a real bawler"