conserve

1. (transitive) To save for later use, sometimes by the use of a preservative.Examples: "to conserve fruits with sugar"; "the amity which […] they meant to conserve and maintain with the emperor"; "Also the Russian lines over which these locomotives run pass through long stretches of waterless country, where the only alternative to hauling additional water-tank wagons is to conserve the water supply by condensing."transitive

2. (transitive) To protect an environment, heritage, etc.Examples: "Two entrants shared this award for their work on two quite different stations, but with the same purpose of bringing a redundant station building back into use for the benefit of the community, with the added result of conserving an historic building. Saltash Town Council bought Saltash station building after it had become very decrepit and 'an eyesore' - such that it was nearly pulled down to make way for housing."transitive

3. (physics, chemistry, intransitive) To remain unchanged during a processintransitive