Adjutant High Priest.
The name sagenkahn Segan Kohen
is the adjutant high priest during second Temple times. One didn't become a full fledged Kohen Gadol until one held the post of Segan Kohen. (See Pirket Avot III, 2; Tractate Yome III, 9 and 41). This name appears once in the Talmun mentioning one of the sages whose name was Chanina SEGAN-HACOHANIM.