1. A book containing maps and vital statistics relating to geographic regions: "For her trip to France, Dorene bought an atlas of maps with illustrations."

"Atlases are usually big, oversized books which have maps, diagrams, and other information; such as, population figures, distances, pictures, and charts."

"The atlas has been used in the wider sense of a collection of maps with illustrations of topographical features, portraits, and pictures of plants and animals, mythological scenes, historical events, etc."

2. An architecture figure of a man which is used as a support: "An atlas is a figure of a man, either standing or kneeling, that is used to hold the upper part of a classical building.
3. A ringlike bone in tetrapods (four-footed creatures) that forms the first neck (cervical) vertebra of the vertebral column, on which the skull rests: "In reptiles, birds, and mammals, the atlas moves with the skull to allow nodding of the head and articulates with the axis to allow rotatory movements."
4. In general anatomy, referring to the top bone in neck: the vertebra that is at the top of the spinal column and which supports the skull: "The atlas locks with the skull on rotation and turns with the head."

"The anatomical name, atlas, refers to the first vertebra; so called, because it holds up the skull (globe). It was named by the Belgian anatomist Andreas Vesalius (1514-1564)."

A book of charts of the sky: "The early celestial atlases were not intended to be guides for amateur star-gazers, but for the use of working astronomers, as a background on which to determine the changing positions of the moon, planets, and comets."

A book of maps showing the various changes that have occurred over a specified period of time in a certain geographic area or in the development of a spatial event (examples: "Historical atlases usually contain more text than a standard atlas, with maps that are usually placed next to the passages they are intended to explain."

"A historical atlas may also have a chronology, or timeline, and biographical notes about the people whose names appear in the text."

A book of maps of a country and which usually contains at least one overview map, individual maps of the major administrative units (states, counties, departments, etc.), and various thematic maps of the entire country, showing populations, land uses, economic activities, etc.: "National atlases often consist of statistical information about the nation in the form of tables and graphs, and they may be published in association with a national mapping agency or government department."

A book of printed maps that is small enough to fit into the pocket of a jacket, usually provided for travelers: "The maps in pocket atlases usually show a geographic area and sometimes have maps that fold out."

"Pocket atlases of the human anatomy are published for medical practitioners in order to provide quick information when they are in the field with their patients and away from their medical centers."

A reference book that is usually very large: "A world atlas contains maps of all the countries and regions of the world, printed in color, sometimes with explanatory text and statistical information, with an index of place names in the back."