An amateur is generally considered a person attached to a particular pursuit, study, or science, without formal training or pay. Conversely, an expert is generally considered a ...

Amateur astronomy, a subset of astronomy, is a hobby whose participants enjoy studying and observing celestial objects.

The word amateur is normally used to mean: somebody who does something (e.g. a job) without being paid for it, or without having had training or education for it.

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Contesting Online - Amateur (ham) radio contesting community web site featuring news, articles, forums, links, and surveys