A person whom one has supported but now behaves treacherously towards one.
More example sentences
- Thank goodness one politician opposed their entry - or we could have this viper in our bosom!
- Apparently he has been unconsciously nursing a viper in his bosom, for the same Science now ‘turns and strikes him.’
- Why nourish a viper in one's bosom, cultivate an adversary, possibly an enemy?
Definition of viper in one's bosom in:
- The US English dictionary