Lewis Short
post-princĭpĭa (noun N) : principium
* Continuance of a thing after it is begun, course, progress, sequel (ante-class.): ut quisque (quidque occeperit), sic ei procedunt postprincipia,Plaut. Pers. 4, 1, 4: voluptas disciplinarum in postprincipiis exsistit, in principiis vero ipsis ineptae et insuaves videntur, Varr. ap. Gell. 16, 18, 6; 16, 9, 5: postprincipia atque exitus vitiosae vitae, old poet ap. Cic. Sest. 55, 118 (Halm reads post principia).
Charlton T. Lewis, Charles Short, A Latin Dictionary