The word 'usurper' has a direct lineage from Latin. Its core, 'usurp', originates from the Latin verb usurpare, meaning "to seize for use" or "to take into possession". This verb itself is a compound of usu (a form of usus, meaning "use") and rapere (meaning "to seize"), painting a vivid picture of the act: to seize something for one's own use. The agent suffix '-er', of Germanic origin, was later appended in English to create the noun, specifying the person who commits this act of wrongful seizure. Thus, a 'usurper' is etymologically one who forcibly takes and uses a position or property that rightfully belongs to another.

Structure: usurp + er - usurp: From Latin usurpare (to seize for use, take possession of). The functional role is the core verb meaning "to take by force". - er: From Old English -ere, an agent noun suffix indicating "one who performs an action". Its functional role is to form a noun meaning "a person who usurps".