Diffusible refers to a substance or a property that can spread out or disperse easily. There are various synonyms for diffusible that can be used depending on the context. Some of these synonyms include disseminative, dispersible, permeable, penetrable, and pervious. Disseminative means capable of spreading widely, while dispersible means able to be spread out evenly. Permeable, penetrable, and pervious all denote the ability of a substance or object to allow other substances to pass through easily. The choice of synonym for diffusible depends on the nature of the material or property under discussion, as well as the intended connotations of the speaker or writer.