klick

Etymology 1

* Most likely a pseudo-condensed pronunciation of kilometer, being a suitably short word emphasizing k+l instead of /keɪ/ alone (the same principle as with military spelling alphabets, but also clearly distinguished from kilo (/kiːloʊ/) for kilogram). * Possibly onomatopoeic of the sound of a military odometer.

noun

1. (slang, military) A kilometer.
   an asteroid between one and three kilometers wide had slammed into the ground at fifteen klicks per second. 2002, Robert J. Sawyer, Hominids
2. (slang, usually in the plural) Kilometres per hour.

Etymology 2

noun

1. Alternative spelling of click