Effusive

Ef‐fu″sive (?), a. Pouring out; pouring forth freely. “Washed with the effusive wave.” Pope.

Effusive rocks(Geol.), volcanic rocks, in distinction from so-called intrusive, or plutonic, rocks.

— Ef‐fu″sive‐ly, adv. — Ef‐fu″sive‐ness, n.