nanometre vs nanometer

nanometre and nanometer both are nouns.

Word	Noun	Adjective	Verb	Adverb
nanometre	Yes	No	No	No
nanometer	Yes	No	No	No

As nouns, nanometre and nanometer are synonyms defined as:

nanometre and nanometer: a metric unit of length equal to one billionth of a meter

Other synonyms of nanometre include micromillimeter, micromillimetre, millimicron, nm.

nanometre (noun)	nanometer (noun)
a metric unit of length equal to one billionth of a meter	a metric unit of length equal to one billionth of a meter