口くち約やく束そく

noun, noun or participle which takes 'suru', transitive verb, intransitive verb

verbal promise; one's word

A promise made orally, without a written contract. Often implies a less binding commitment, and can carry a nuance of unreliability compared to a written agreement.

• 口くち約やく束そくだけでは不ふ安あんなので、契けい約やく書しょを作さく成せいしましょう。

  I'm uneasy with just a verbal promise, so let's draw up a written contract.