kilometre vs km

kilometre and km both are nouns.

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

As nouns, kilometre and km are synonyms defined as:

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

Other synonyms of kilometre include kilometer, klick.

kilometre (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)