effuse

Effuse is a verb meaning to pour forth, emit, or radiate, often with a sense of steady or abundant release. It can describe liquids, gases, light, heat, or a fragrance escaping from a source. The related noun is effusion, which denotes the act or instance of effusing or the substance that has been effused. In casual usage, effuse may appear in phrases such as a bottle effusing fragrance or a body refusing fluids, though more common terms are emit, release, or discharge.

Etymology and related forms: Effuse derives from Latin effundere, to pour out, with the sense of pouring or flowing forth extended into English. The adjective effusive is used to describe something that pours forth in generous quantities or, in geology and volcanology, lava that flows out onto the surface.

Scientific usage: In physics and chemistry, effuse describes the emission of gas through a small opening, a process known as gas effusion. In this context, the term emphasizes the outward flow of particles, often analyzed by laws such as Graham’s law. In medicine, effusion is the term for fluid that accumulates or escapes into a body cavity, while effuse as a verb is far less common in modern clinical writing.

Other contexts: In volcanology, effusive eruptions refer to lava flows that steadily pour out of a volcano, in contrast to explosive eruptions that eject ash and gas. The word can also describe light or heat that seems to pour from a source, as in “the room effused warmth.”

Notes: While usable, effuse as a verb is relatively formal or archaic in everyday language; effusion and emission are more commonly encountered.