betterment, improvement, advance - a change for the better; progress in development

preservation, saving - the activity of protecting something from loss or danger

conservancy - the official conservation of trees and soil and rivers etc.

soil conservation - protection of soil against erosion or deterioration

oil conservation - the conservation of petroleum resources

water conservation - the conservation of water resources

principle - a basic truth or law or assumption; "the principles of democracy"

natural philosophy, physical science, physics - the science of matter and energy and their interactions

conservation of charge, conservation of electricity - the principle that the total electric charge of a system remains constant despite changes inside the system

conservation of energy, first law of thermodynamics, law of conservation of energy - the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes

conservation of mass, conservation of matter, law of conservation of mass, law of conservation of matter - a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system

conservation of momentum - the principle that the total linear momentum in a closed system is constant and is not affected by processes occurring inside the system

conservation of parity, mirror symmetry, space-reflection symmetry, parity - (physics) parity is conserved in a universe in which the laws of physics are the same in a right-handed system of coordinates as in a left-handed system