from
The Collaborative International Dictionary of English v.0.48
Occlusion \Oc*clu"sion\, n. [See {Occlude}.]
1. The act of occluding, or the state of being occluded.
[1913 Webster]
Constriction and occlusion of the orifice. --Howell.
[1913 Webster]
2. (Med.) The transient approximation of the edges of a
natural opening; imperforation. --Dunglison.
[1913 Webster]
{Occlusion of gases} (Chem. & Physics), the phenomenon of
absorbing gases, as exhibited by platinum, palladium,
iron, or charcoal; thus, palladium absorbs, or occludes,
nearly a thousand times its own volume of hydrogen, and in
this case a chemical compound seems to be formed.
[1913 Webster]