口くち先さきだけ

expression, noun which may take the genitive case particle 'no'

all talk; insincere; empty words

Describes someone who says things without real intention or ability to follow through. Often used critically: 口先だけの人 (a person who is all talk).

• 彼かれの謝しゃ罪ざいは口くち先さきだけだった。

  His apology was just empty words.

• 口くち先さきだけの約やく束そくはしないでほしい。

  I wish you wouldn't make promises that are just talk.