What is level, smooth, or equal in surface; not rough; free from irregularities; hence uniform in rate of motion of action; as, even ground; an even speed; an even course of conduct called?

even — Level, smooth, or equal in surface; not rough; free from irregularities; hence uniform in rate of motion of action; as, even ground; an even speed; an even course of conduct. (Webster's 1913.)

Sources