Diffuso

Diffuso is an Italian adjective derived from Latin diffusus, the past participle of diffundere, meaning “poured forth” or “spread.” In ordinary use it describes something that is distributed over a wide area or that lacks sharp boundaries. It can refer to physical spread (una macchia diffusa) or to figurative use (una notizia diffusa). The term is often contrasted with localizzato, which denotes a localized distribution.

In scientific and clinical language, diffuso has specialized senses. In medicine, a condition described as diffuso is disseminated throughout an organ or body, as opposed to focal or localized lesions, for example infiltrazioni polmonari diffuse. In physics and optics, diffuse describes light that is scattered in many directions, producing a soft, non-directional illumination (riflessione diffusa). In ecology and geography, patterns are described as diffusi when they occur across broad areas rather than being restricted to a single site.

In everyday language diffuso can also describe media or phenomena that are widespread or frequently encountered, such as una notizia diffusa through channels, or una pratica diffusa in una comunità. The word has cognates in other Romance languages; Spanish uses difuso or difusa and Portuguese uses difuso with similar meaning, reflecting shared Latin roots. See also diffusion, diffuse illumination, localized versus diffuse.