憎まれ口

1. Origins, structure, and basic meaning

• Structure: 憎まれ口 (にくまれぐち) is a noun for a snide or spiteful remark.
• Basic usage: 憎まれ口をたたく describes making a barbed comment; 憎まれ口ばかり言う depicts a repeated tendency to do so.

2. Common pitfalls and similar expressions

• The set phrase 憎まれ口をたたく
  • たたく is not literal hitting here; together the words mean making a snide remark. ばかり adds the idea of doing little else.