decarbonize /diːˈkɑːbənaɪz/ verb4 •To remove carbon from something. •To reduce or replace fossil fuels by renewable energy in energy production and distribution systems.Efforts to decarbonize the automotive fleet are challenging, but no one wants nightmare-grade climate change, either.Efforts to decarbonize have been facing some challenges lately. •To clean hard sooty deposits from inside an internal combustion engine.During the overhaul, the cylinder heads were found to be reusable, as long as they got a good cleaning to decarbonize the valve seat areas. •To remove carbon content from iron or steel, either intentionally or accidentally, as by (for example) overheating steel in the presence of air, destroying its former temper and hardness.A blast furnace decarbonizes iron enough that it can be used as input to a steelmaking furnace.Repeatedly scorching a case-hardened tool will ruin the case by decarbonizing it. formsdecarbonized · decarbonizing · decarbonizes