Definition of polysynthetism in English:

polysynthetism

Pronunciation /ˌpɒlɪˈsɪnθətɪz(ə)m/

noun

rare Linguistics

Origin

Mid 19th century; earliest use found in Frederic Farrar (1831–1903), dean of Canterbury, novelist, and philologist. From polysynthet- + -ism.