4 adjectives to describe closure

The second sound is, without doubt, caused by the sudden closure of the semilunar valves of the pulmonary artery and the aorta, at the moment when the contraction of the ventricles is completed.

Within the guilty closure of thy walls, Richard II.

The author really has no right to choose only the critical moments, and to shut out the commonplace, every-day life by a sort of literary closure.

Death as a rule results from either sheer exhaustion or failure of breath through the spasmodic closure of the glottis.

4 adjectives to describe  closure