bes·ti·al·i·ty 
(bĕs′chē-ălĭ-tē, bēs′-)
(bĕs′chē-ălĭ-tē, bēs′-)n. pl. bes·ti·al·i·ties
1. The quality or condition of being an animal or like an animal.
2. Conduct or an action marked by depravity or brutality.
3. Sexual relations between a human and an animal.