A venomous snake, taken as the type of malignancy and treachery, but whose flesh was formerly believed to have great nutritive or restorative properties, and was used medicinally. Early allusive references include some to the statement in Pliny's Natural History that the female viper was killed by her young eating their way out at birth.
Recorded from the early 16th century, the word comes ultimately from Latin vivus ‘alive’ + parere ‘bring forth’.
viper in one's bosom a person who betrays those who have helped them; from the fable (found in Aesop) of the viper which was reared or warmed in a person's bosom, and which ended by biting its nurturer.
Subjects: Zoology and Animal Sciences.