also multi-national, by 1921, "comprising or pertaining to many nations," from multi- + national. Originally with reference to states; later (by 1960) to corporations and organizations. As a noun, short for multinational corporation (itself attested by 1956), one having branches, offices, etc. in many countries, it is attested by 1971.
in geometry, "a plane figure with numerous angles," 1570s, from Late Latin polygonum, from Greek polygōnon, noun use of neuter of adjective polygōnos "many-angled," from polys "many" (from PIE root *pele- (1) "to fill") + -gōnos "angled," from gōnia "angle, corner" (from PIE root *genu- (1) "knee; angle"). Related: Polygonal.
"having or tinted with several or many colors," 1816, from French polychrome, from Latinized form of Greek polykhrōmos (also polykhrōmatos) "many-colored" (see poly- + chrome). As a noun from 1800, "work of art decorated in several colors;" by 1838 as "a fluorescent substance forming prismatic crystals." Related: Polychromic; polychromatic; polychromate.