cosmology

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The study of the physical universe considered as a totality of phenomena in time and space.
2. n. The astrophysical study of the history, structure, and constituent dynamics of the universe.
3. n. A specific theory or model of this structure and these dynamics.

Century Dictionary and Cyclopedia

1. n. The general science or theory of the cosmos or material universe, of its parts, elements, and laws; the general discussion and coördination of the results of the special sciences.
2. n. That branch of metaphysics which is concerned with the a priori discussion of the ultimate philosophical problems relating to the world as it exists in time and space, and to the order of nature.

Wiktionary

1. n. The study of the physical universe, its structure, dynamics, origin and evolution, and fate
2. n. A metaphysical study into the origin and nature of the universe
3. n. A particular view (cultural or religious) of the structure and origin of the universe

GNU Webster's 1913

1. n. The branch of science or philosophy dealing with the origin and nature of the universe as a whole.
2. n. (Philosophy) the branch of metaphysics speculating on the structure and nature of the most fundamental parts of the system of creation, such as space and time, the elements of bodies, the structure of the universe, the modifications of material things, causality, the laws of motion, and the order and course of nature.
3. n. (Astronomy) the branch of astronomy dealing with the origin and structure of the universe, including the evolution of its present observable structure, using the methods of observational astronomy as well as mathematical physics.
4. n. a treatise dealing with the original and structure of the universe.

WordNet 3.0

1. n. the branch of astrophysics that studies the origin and evolution and structure of the universe
2. n. the metaphysical study of the origin and nature of the universe