A hobby is a spare-time recreational pursuit.

Etymology

thumb|250px|In the 18th-century novel The Life and Opinions of Tristram Shandy, Gentleman, the characters' hobby-horses, or particular obsessions, are discussed in detail. Here, Uncle Toby's obsession with the military leads to him and Trim - who gets caught up in Toby's enthusiasm - to begin acting out military actions. Illustration by George Cruikshank. A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse (which was sometimes called a "Hobby"). From this came the expression "to ride one's hobby-horse", meaning "to follow a favourite pastime", and in turn, hobby in the modern sense of recreation.

Hobbies are practiced for interest and enjoyment, rather than financial reward. Examples include collecting, creative and artistic pursuits, making, tinkering, sports and adult education. Engaging in a hobby can lead to acquiring substantial skill, knowledge and experience. However, personal fulfillment is the aim.

What are hobbies for some people are professions for others: a chef may enjoy playing computer games as a hobby, while a professional game tester might enjoy cooking. Generally speaking, the person who does something for fun, not remuneration, is called an amateur (or hobbyist), as distinct from a professional.

An important determinant of what is considered a hobby, as distinct from a profession (beyond the lack of remuneration), is probably how easy it is to make a living at the activity. Almost no one can make a living at cigarette card or stamp collecting, but many people find it enjoyable; so it is commonly regarded as a hobby.

Amateur astronomers often make meaningful contributions to the professionals. It is not entirely uncommon for a hobbyist to be the first to discover a celestial body or event.Fact: date=December 2007

In the UK, the pejorative noun anorak (similar to the Japanese "otaku", meaning a geek or enthusiast) is often applied to people who obsessively pursue a particular hobby that is otherwise considered boring, such as train spotting or stamp collecting.

Development of hobbies into other ventures

Whilst some hobbies strike many people as trivial or boring, hobbyists have found something compelling and entertaining about them. Much early scientific research was, in effect, a hobby of the wealthy; more recently, Linux began as a student's hobby. A hobby may not be as trivial as it appears at a time when it has relatively few followers. Thus a British conservationist recalls that when seen wearing field glasses at a London station in the 1930s he was asked if he was going to the (horse) races.Fact: date=March 2007 The anecdote indicates that at the time an interest in nature was not widely perceived as a credible hobby. Practitioners of that hobby went on to become the germs of the conservation movement that flourished in Britain from 1965 onwards and became a global political movement within a generation. Conversely, the hobby of aircraft spotting probably originated as part of a serious activity designed to detect arriving waves of enemy aircraft entering English airspace during World War II.Fact: date=March 2007 In peacetime it usually has no such practical or social purpose.