The Blackwell dictionary of sociology - Allan Johnson

Written by a sociologist who is also an accomplished writer and teacher, this is a dictionary of sociology aimed primarily at students, but it will also be of use to professionals looking for an introduction to core concepts outside their areas of expertise. It is unique in its combination of lucid prose, engaging examples, a single author's overview, and its minimal assumptions about the average reader's prior knowledge of sociology and related fields, such as philosophy and economics.
This dictionary defines amorphous and fuzzy sociological concepts in a clear and sensible way. This dictionary is an invaluable reference tool, providing a lively and engaging introduction to the basics of what it means to think in a sociological way.