American spelling vs metacenter

American spelling and metacenter both are nouns.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
metacenter	Yes	No	No	No

American spelling (noun)	metacenter (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	(shipbuilding) the point of intersection between two vertical lines, one line through the center of buoyancy of the hull of a ship in equilibrium and the other line through the center of buoyancy of the hull when the ship is inclined to one side; the distance of this intersection above the center of gravity is an indication of the stability of the ship