hol·o·ceph·a·lan I. \| ̷ ̷ ̷ ̷| ̷ ̷ ̷ ̷lən\adjective orhol·o·ce·pha·li·an\|hälōsə|fālēən, |hōl-\ Etymology: New Latin Holocephali + English -an or -ian : of or relating to the subclass Holocephali II. noun orholocephalian\“\ (-s) : a fish of the subclass Holocephali