americiu Noun, n, americiu americium (chemical element) Appox. usage (any sense): 0.015 per million words Appox. usage (any sense): 0.015 per million words
americium Noun, n, americium alternative form of americiu Appox. usage (any sense): less than 0.1 per million words Appox. usage (any sense): less than 0.1 per million words