mid-15c., contentement, "satisfactory payment" (of a debt; a sense now obsolete), from Old French contentment, from contenter (see content (v.)). Meaning "That happiness which consists in being satisfied with present conditions" is from 1590s.
Contentment is passive; satisfaction is active. The former is the feeling of one who does not needlessly pine after what is beyond his reach, nor fret at the hardship of his condition; the latter describes the mental condition of one who has all he desires, and feels pleasure in the contemplation of his situation. A needy man may be contented, but can hardly be satisfied. [Century Dictionary]