km vs klick

km and klick both are nouns.

Word	Noun	Adjective	Verb	Adverb
km	Yes	No	No	No
klick	Yes	No	No	No

As nouns, km and klick are synonyms defined as:

km and klick: a metric unit of length equal to 1000 meters (or 0.621371 miles)

Other synonyms of km include kilometer, kilometre.

km (noun)	klick (noun)
a metric unit of length equal to 1000 meters (or 0.621371 miles)	a metric unit of length equal to 1000 meters (or 0.621371 miles)