Hydrogenise is a word that means to combine hydrogen with a substance or to treat a substance with hydrogen. There are various synonyms for hydrogenise, including hydrogenate, dehydrogenate, hydridize, hydrolize, and hydrotreat. Hydrogenate is perhaps the most commonly used synonym for hydrogenise and refers to the process of adding hydrogen to a molecule. Dehydrogenate, on the other hand, refers to the removal of hydrogen from a compound. Hydridize means to combine hydrogen with a non-metallic element, while hydrolize refers to the process of adding water to break down a compound. Finally, hydrotreat means to treat a substance with hydrogen under specific conditions to alter its physical or chemical properties.