{v. phr.} To speak or to argue with no result; do nothing by talking. * /The teacher saw that she was wasting her breath; the children refused to believe her./ * /I know what I want. You're wasting your breath./
WASTE ONE'S BREATH
Meaning of WASTE ONE'S BREATH in English
Slang English vocab. Английский сленговый словарь. 2012