1. (n.) The act of usurping, or of seizing and enjoying; an authorized, arbitrary assumption and exercise of power, especially an infringing on the rights of others; specifically, the illegal seizure of sovereign power; -- commonly used with of, also used with on or upon; as, the usurpation of a throne; the usurpation of the supreme power.

2. (n.) Use; usage; custom.

accession adoption anointing anointment appointment appropriation arrogation assignment assumption authorization colonization conquest consecration coronation delegation deputation election empowerment encroachment enslavement incursion indent infraction infringement inroad intrusion invasion legitimate succession occupation overstepping playing God preemption preoccupation prepossession requisition seizure subjugation succession takeover taking over transgression trespass trespassing