Definition of: usurp

(y·zûrp′, -sûrp′) v.t.
1. To seize and hold (the office, rights, or powers of another) without right or legal authority; take possession of by force.
2. To take arrogantly, as if by right.
—v.i.
3. To practice usurpation; encroach: with on or upon. See synonyms under ASSUME. [<OF usurper <L usurpare make use of, usurp,? <O usususe + rapere seize]
—u·surp′er noun
—u·surp′ing·ly adverb