centre of gravity vs center of gravity

centre of gravity and center of gravity both are nouns.

Word	Noun	Adjective	Verb	Adverb
centre of gravity	Yes	No	No	No
center of gravity	Yes	No	No	No

As nouns, centre of gravity and center of gravity are synonyms defined as:

centre of gravity and center of gravity: the point within something at which gravity can be considered to act; in uniform gravity it is equal to the center of mass

centre of gravity (noun)	center of gravity (noun)
the point within something at which gravity can be considered to act; in uniform gravity it is equal to the center of mass	the point within something at which gravity can be considered to act; in uniform gravity it is equal to the center of mass