Effusion (disambiguation)

Effusion is the process of gases passing through a small hole.

Effusion may also refer to:

Medicine
The seeping of fluid into a body cavity, the fluid itself, or an abnormal collection of fluid in a body cavity or space:
 * Ascites
 * Pericardial effusion
 * Pleural effusion
 * Joint effusion
 * Subdural Effusion
 * Mastoid Effusion
 * Knee effusion
 * Sometimes called "hydrops"

Geology

 * Effusive eruption, an effusion of lava from a volcano