Derived words: naptanu ‘food allotment, meal, banquet; time of the evening meal, evening’ (CAD N₁ 319, AHw. 741); patnu ‘meal, repast(?)’ (CAD P 278); putannatu (putunnatu) ‘food provisions(?)’ (CAD P 546); pitennu (a ritual meal) (CAD P 434).
No etymology can be suggested.