1.NounThe mathematics of numbers (integers, rational numbers, real numbers, or complex numbers) under the operations of addition, subtraction, multiplication, and division.
2.NounNumber theory.
3.AdjectiveIncreasing or decreasing by an arithmetic progression.
"Growth in the most mature markets is likely to be arithmetic; on what rational basis could one hope for exponential growth there?"
4.AdjectiveOf, relating to, or using arithmetic; arithmetical.
"arithmetic geometry"
5.AdjectiveOf a progression, mean, etc, computed solely using addition.