Definitions of conserve:

• noun:   fruit preserved by cooking with sugar
• verb:   preserve with sugar

  Example: "Mom always conserved the strawberries we grew in the backyard"

• verb:   use cautiously and frugally

  Example: "Conserve your energy for the ascent to the summit"

• verb:   keep in safety and protect from harm, decay, loss, or destruction

  Example: "Children must be taught to conserve our national heritage"

• verb:   keep constant through physical or chemical reactions or evolutionary change

  Example: "Energy is conserved in this process"