Enzymes that catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the removal of water. EC 4.2.1.

Synonyms: Hydrases, Hydro-Lyases, Hydro Lyases, Hydrase, Hydro Lyase, Hydro-Lyase, Dehydratases, Dehydratase, Lyases, Hydro, EC 4.2.1.-, Lyase, Hydro