D defs.my
Entry 2 senses Webster, 1913

Usurpation

/yo͞osˌ-ẽrp-āsh'-ən/ · U·sur·pa·tion · IPA /ˌjuː.sə(ɹ)ˈpeɪ.ʃən/
01 n. The act of usurping, or of seizing and enjoying; an authorized, arbitrary assumption and exercise of power, especially an infringing on the…
  1. 1.
    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.
    “He contrived their destruction, with the usurpation of the regal dignity upon him.” — Sir T. More.
    “A law [of a State] which is a usurpation upon the general government.” — O. Ellsworth.
    “Manifest usurpation on the rights of other States.” — D. Webster.
  2. 2.
    Use; usage; custom.[Obs.]