Definition of polysynthesis in English:

polysynthesis

noun

Linguistics
  • The incorporation of several or all syntactic elements in a sentence into one word; this as a characteristic feature of certain languages.

Origin

Mid 19th century; earliest use found in Francis Lieber (1800–1872). From poly- + synthesis, after polysynthetic.

Pronunciation

polysynthesis

/ˌpɒlɪˈsɪnθɪsɪs/