effúzív

Effúzív is an adjective used in several languages to denote something poured out or expressed openly. It appears in both scientific and literary contexts, where it describes different kinds of outward flow—geological and emotional.

In geology, effúzív (often rendered in English as effusive) refers to eruptions in which magma reaches the surface as lava flows rather than erupting violently. Effusive eruptions produce lava flows that form features such as lava fields, channels, and textures like pahoehoe and aa, as well as lava domes and sometimes extensive lava sheets. They are typically characterized by lower explosivity and gases compared with explosive eruptions, though individual eruptions can vary in intensity and duration. Examples are lava flows associated with shield volcanoes and basaltic volcanism, with well-known activity occurring in places such as Hawaii.

In general or literary use, effúzív describes expressions of emotion, warmth, or gratitude that are unrestrained or demonstrative. An effusive greeting or speech conveys strong, outward-facing sentiment, and is often contrasted with restrained or formal prose.

Etymology: the term derives from Latin effusus “poured out,” through French effusif and related forms. The exact spelling and diacritics vary by language, with dialectal or orthographic differences affecting appearance as effusivo or efusiv in non-accented forms.

See also: effusive, effusion, lava flow, volcano.