—n.
1 a the science of numbers. b one's knowledge of this (have improved my arithmetic).
2 the use of numbers; computation (a problem involving arithmetic).
—adj. (also arithmetical) of or concerning arithmetic.
Phrases and idioms:
arithmetic mean the central number in an arithmetic progression. arithmetic progression
1 an increase or decrease by a constant quantity (e.g. 1, 2, 3, 4, etc., 9, 7, 5, 3, etc.).
2 a sequence of numbers showing this.
Derivatives:
arithmetician n.
Etymology: ME f. OF arismetique f. L arithmetica f. Gk arithmetike (tekhne) art of counting f. arithmos number
Useful english dictionary. 2012.