Dictionaries provide short definitions (a sentence or two, or a short paragraph) of terms as used in economics or a brief overview of an economist. Encyclopedias contain longer entries that provide a more in-depth information on major economics topics.
An economic indicator is a piece of economic data that can be used to form statistics about an economic activity. They can be used for the analysis of economic performance and predictions of future performance. Below are some introductory resources you can use about this topic: