Meaning

noun everything that exists anywhere

noun any of various mostly Mexican herbs of the genus Cosmos having radiate heads of variously colored flowers and pinnate leaves; popular fall-blooming annuals

originFrom Middle English cossmos (“the universe; the world”), borrowed from Ancient Greek κόσμος (kósmos, “order; universe; the earth, the world; decoration, ornament”), ultimately from Proto-Indo-European *ḱens- (“to announce, proclaim; to put in order”). The plural form cosmoi is a learned borrowing from Ancient Greek κόσμοι (kósmoi).

Etymology from Wiktionary, CC BY-SA 3.0