Serenianus
Could not find Serenianum in Logeion dictionaries.
Serenianum Proper-name noun: masculine accusative singular of Serenianus
Sĕrēnĭānus, ī, m. , favori de Vibius Gallus, frère de Julien : Amm.
Serenia'nus, Ae'lius
a member of the consilium of the emperor Alexander Severus, is called by Lampridius "omnium vir sanctissimus." (Alex. Sever. 68.)