dekameter vs decametre

dekameter and decametre both are nouns.

Word	Noun	Adjective	Verb	Adverb
dekameter	Yes	No	No	No
decametre	Yes	No	No	No

As nouns, dekameter and decametre are synonyms defined as:

Other synonyms of dekameter include dam, decameter, dekametre, dkm.

dekameter (noun)	decametre (noun)
a metric unit of length equal to ten meters	a metric unit of length equal to ten meters