Lewis & Short

quippĭ-ni (quippĕni), adv. [quippeni], why not? or, affirmatively, certainly, to be sure, by all means (ante- and post-class.), Plaut. Men. 5, 9, 50; id. Poen. 3, 4, 21; 28; 30; App. M. 9, p. 229, 15: Chr. Quid? illam meretricemne esse censes? Ni. Quippeni? Plaut. Bacch. 4, 7, 41; id. Ps. 4, 1, 12.