per-diffĭcĭlis — Lewis & Short
per-diffĭcĭlis, e, adj.,
I very difficult (class.), Cic. Part. 24, 84:
quaestio,id. N. D. 1, 1, 1:
navigatio,id. Att. 3, 8, 2.—Sup.:
perdifficillimus aditus,exceedingly difficult, Liv. 40, 21.—Adv.: perdiffĭcĭlĭter, with great difficulty, Cic. Ac. 2, 15, 47.