a person's head removed and put on a pike (a weapon formerly used by foot soldiers consisting of a metal spearhead on a long wooden shaft). Used figuratively to mean an
example of
discipline.
But sooner or later somebody will decide that it's too enturbulent right now in that particular course and so they'll go look in the ethics files, and they add them all up, and they find one nice, fat file, and they feel they need a head on a pike so there is Doakes.