[oc.clu.sion] n [L occludere] (ca. 1645) 1: the act of occluding: the state of being occluded: as a: the complete obstruction of the breath passage in the articulation of a speech sound b: the bringing of the opposing surfaces of the teeth of the two jaws into contact; also: the relation between the surfaces when in contact c: the inclusion or sorption of gas trapped during solidification of a material
2: the front formed by a cold front overtaking a warm front and lifting the warm air above the earth's surface