Hi vis overalls - High visibility overalls are used by workers on the roads, rails, and near cranes etc. Padded overalls - With padding material covering the inside for use in cold weather This definition was written in the context of Personal Protective Equipment (PPE)
Princeton's WordNet(0.00 / 0 votes)Rate this definition: conservation of mass, conservation of matter, law of conservation of mass, law of conservation of matter(noun) a fundamental principle of classical physics that matter cannot be created or destroyed in an isolated system. Chaldean Numerology.
Definition of conservation for English Language Learners. : 1  the protection of animals, plants, and natural resources. : 2  the careful use of natural resources (such as trees, oil, etc.) to prevent them from being lost or wasted. : 3  the things that are done to keep works of art or things of historical importance in good condition.