conserve
Definitions
To protect something from harm, decay, or loss, especially an environmentally or culturally significant resource.
To use a resource carefully and sparingly to avoid waste.
To preserve fruit or other food by cooking it with sugar.
Examples
We must learn to conserve water during the dry summer months.
The organization works tirelessly to conserve the natural habitat of endangered species.
He decided to conserve his energy for the final sprint of the race.