What does it mean to dream about cosmos?
The cosmos usually points to the whole of things, a sense of order, mystery, or your small place in a vast scheme.
Four ways to read it
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream.
Freud
Freud would look at the whole sweep of space as the dreamer's wish to grasp the largest meaning, the self set against everything. Such a view can carry awe or a fear of insignificance. The feeling it leaves is the clue.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
Jung might see the cosmos as an image of the Self in its fullest reach, the whole within which the psyche finds its place. It can mark a sense of unity with all things. The vast order mirrors an inner wholeness.
Jungian concept (our summary).Modern
Continuity ties the cosmos to waking thoughts of meaning, scale, and one's place in the wider world. It often follows reflection on the big questions. The vast space mirrors the size of the thought.
Continuity hypothesis (our summary).Mythological
The cosmos was pictured as an ordered whole in tradition after tradition, drawn out of chaos by the gods and held in balance. The word itself meant order. It stood for the harmony binding all things from earth to the farthest sky.
Rosmerta Publishing editorial synthesis (after Bulfinch; Brewer).