late 14c., from Latin suffusionem (nominative suffusio) "a pouring over," from suffusus, past participle of suffundere "pour upon, overspread, suffuse," from sub "under" + fundere "to pour" (see found (v.2)).
suffusion suf·fu·sion (sə-fyōō'zhən)
The act of pouring a fluid over the body.
The condition of being wet with a fluid.
A spreading out of a body fluid from a vessel into the surrounding tissues.
The reddening of a surface.