keep constant through physical or chemical reactions or evolutionary change; Energy is conserved in this process'
keep in safety and protect from harm, decay, loss, or destruction; We preserve these archeological findings; The old lady could not keep up the building; children must be taught to conserve our national heritage; The museum curator conserved the ancient manuscripts
use cautiously and frugally; I try to economize my spare time; conserve your energy for the ascent to the summit
preserve with sugar; Mom always conserved the strawberries we grew in the backyard'