Lewis & Short

per-blandus, a, um, adj., very courteous or charming, very engaging, very bland: successor, Cic. Q. Fr. 1, 2, 3: oratio, Liv. 23, 10, 1: adulatio, Juvenc. 1, 705.
Adv.: perblandē, very winningly: aliquem salutare, Macr. S. 1, 2, 16.