u·sur·pa·tion 
(y′sər-pāshən, -zər-)
(y′sər-pāshən, -zər-)n.
1. The act of usurping, especially the wrongful seizure of royal sovereignty.
2. A wrongful seizure or exercise of authority or privilege belonging to another; an encroachment: "in our own day, gross usurpations upon the liberty of private life" (John Stuart Mill).
- atrociously
- atrociousness
- atrocity
- atrophic
- atrophy
- atropin
- atropine
- Atropos
- ATSC
- at sea
- at service
- at sign
- Atsina
- at sixes and sevens
- at (someone's) beck and call
- at someone's beck and call
- at (someone's) door
- at someone's door
- at (someone's) feet
- at someone's feet
- at (someone's) service
- at someone's service
- at speed
- at stake
- at stud