Lewis & Short

prīmĭcērĭus, ii, m. [primus-cera; whose name stands first on the wax-coated tablets; hence], the first among those holding a similar office, a chief, head, superintendent (post-class.): primicerius in officio Praefectorum Praetorio, Veg. Mil. 2, 21: protectorum, of the guard, Amm. 18, 3, 5: notariorum, the chancellor or chief of the secretaries, Cod. Th. 11, 18, 1: sacri cubiculi, the head-chamberlain, Cod. Just. 12, 28, 1 et saep.