Main Entry: ef·fu·sion

Pronunciation: \i-ˈfyü-zhən, e-\

Function: noun

Date: 15th century

1 : an act of effusing
2 : unrestrained expression of words or feelings <greeted her with great effusion — Olive H. Prouty>
3 a (1) : the escape of a fluid from anatomical vessels by rupture or exudation (2) : the flow of a gas through an aperture whose diameter is small as compared with the distance between the molecules of the gas b : the fluid that escapes