HP Sassoon(1) 202.2 :פירוסתא דתרבא‏ : the covering of the fat of the lung
See the entire entry for pyrwsh n.f. covering

HP Sassoon(1) 202.2 :כד מינקיב פירוסתא דתרבא דריאה‏ : when the fat of the covering of the lungs is punctured
See the entire entry for traḇ, tarbā n.m. animal fat