1. The universe regarded as an orderly, harmonious whole.

2. An ordered, harmonious whole.

3. Harmony and order as distinct from chaos.

4. pl. cos·mos·es or cosmos Any of various mostly Mexican herbs of the genus Cosmos in the composite family, having radiate flower heads of variously colored flowers and opposite pinnate leaves, especially C. bipinnatus and C. sulphureus, widely cultivated as garden annuals.