con·serve • v. / kənˈsərv/ [tr.] protect (something, esp. an environmentally or culturally important place or thing) from harm or destruction: the funds will help conserve endangered meadowlands. ∎ prevent the wasteful or harmful overuse of (a resource): industry should conserve water. ∎ Physics maintain (a quantity such as energy or mass) at a constant overall total. ∎ (usu. be conserved) Biochem. retain (a particular amino acid, nucleotide, or sequence of these) unchanged in different protein or DNA molecules. ∎ preserve (food, typically fruit) with sugar.• n. / ˈkänˌsərv/ a sweet food made by preserving fruit with sugar; jam.