noun the liquid escaping or exuded.
2. effusion ·noun that which is poured out, literally or figuratively.
3. effusion ·noun the act of pouring out; as, effusion of water, of blood, of grace, of words, and the like.
4. effusion ·noun the escape of a fluid out of its natural vessel, either by rupture of the vessel, or by exudation through its walls. it may pass into the substance of an organ, or issue upon a free surface.