Feudalism was a European political system in which a lord owned all the land while vassals and serfs farmed it. Feudalism ended in the 1400s.
People who lived during feudalism didn't use the term feudalism. In fact, it wasn't until several centuries after this system ended that scholars coined the term feudalism. The ending -ism means "philosophy or system." And feudal comes from the Medieval Latin word feudalis, meaning "feudal estate," and is related to feodary, "one who holds lands of an overlord in exchange for service."