The cosmos (Ancient Greek: κόσμος, romanized: Kósmos, , US also ) is an alternative name for the universe or its nature or order. Usage of the word cosmos implies viewing the universe as a complex and orderly system or entity.

The cosmos is studied in cosmology – a broad discipline covering scientific, religious or philosophical aspects of the cosmos and its nature. Religious and philosophical approaches may include the cosmos among spiritual entities or other matters deemed to exist outside the physical universe.

Etymology

The verb κοσμεῖν (κοσμεῖν) meant generally "to dispose, prepare", but especially "to order and arrange (troops for battle), to set (an army) in array"; also "to establish (a government or regime)", "to adorn, dress" (especially of women). Thus kosmos meant "ornaments, decoration" (compare kosmokomes "dressing the hair," and cosmetic). The philosopher Pythagoras used the term kosmos (Ancient Greek: κόσμος, Latinized kósmos) for the order of the universe. Anaxagoras further introduced the concept of a Cosmic Mind (Nous) ordering all things. The modern Greek κόσμος "order, good order, orderly arrangement" is a word with several main senses rooted in those notions. κόσμος has developed, along with primary "the universe, the world", the meaning of "people" (collectively).