Pronunciation: (pol"ē-sin-thet'ik),[key] —adj. 1. (of a language) characterized by a prevalence of relatively long words containing a large number of affixes to express syntactic relationships and meanings. Many American Indian languages are polysynthetic. Cf. analytic (def. 3), synthetic (def. 3).
2. of or pertaining to polysynthesism. Also,pol"y•syn•thet'i•cal.