kilometer vs km

kilometer and km both are nouns.

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

As nouns, kilometer and km are synonyms defined as:

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

Other synonyms of kilometer include kilometre, klick.

kilometer (noun)	km (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)