The affix ṇamul comes after the verb pur 'to fill' when the word carman and udar are compounded with it.,
Thus उदरपूरं भुङ्क्ते 'he eats so as to fill his belly'? चर्मपूरं स्तृणाति 'he spreads so as to cover the skin'.,
चर्म-उदरयोः पूरेः
Adhyāya 3 · Pāda 4 · Rule 31