The kilometre (American spelling: kilometer), symbol km's a unit of length in the metric system, equal to one thousand metres. It's the conventionally used measurement unit for expressing distances between geographical places in countries which use the metric system. While it's defined exactly as 1000 m, it equals roughly a ten minutes' walk. Slang terms for kilometre include click (sometimes spelled klick or klik) and kay (or k). Pronunciation There're two different pronunciations for the word… (More on Kilometres)