Meaning of rough breathing

rough' breath'ing

Pronunciation: [key]
  1. the symbol (&ain;) used in the writing of Greek to indicate aspiration of the initial vowel or of the &rgr; (rho) over which it is placed.
  2. the aspirated sound indicated by this mark. Cf.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.