[yoo-ser-pey-shuh n, -zer-]
an act of usurping; wrongful or illegal encroachment, infringement, or seizure.
illegal seizure and occupation of a throne.
Origin of usurpation
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
late 14c., from Old French usurpacion, from Latin usurpationem (nominative usurpatio), noun of action from usurpare (see usurp).
Online Etymology Dictionary, © 2010 Douglas Harper