<unk>  refers to inability of<unk>  to expand.  It results as a complication of fibrinous or granulomatous pleuritis.  Fibrinous visceral pleura traps the<unk>  and restricts it from expanding.  Expanded pleural space gets filled with fluid and results in chronic unilateral pleural effusion.
Trapped lung
Round pneumonia
Urinothorax
Pleurisy
Pneumopericardium
Hydrothorax
Hemothorax
Chylothorax