A bicycle is a two-wheeled vehicle that's propelled by foot pedals and steered with handlebars. They say you never forget how to ride a bicycle once you learn.
When you travel to places like Amsterdam and Beijing you'll see people of all ages using bicycles as their major form of transportation. The word bicycle is also a verb, as in "I think I'll bicycle over to the bakery and buy some muffins." The word bicycle was coined in the 19th century from a combination of the Greek bi, or "two," and kyklos, "wheel."