E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Crozier or Crosier.
An archbishops staff terminates in a floriated cross, while a bishops crook has a curved, bracken-like head. A bishop turns his crook outwards, to denote his wider authority; an abbot (whose crook is the same as a bishops) carries it turned inwards, to show that his jurisdiction is limited to his own inmates. When walking with a bishop an abbot covers his crook with a veil hanging from the knob, to show that his authority is veiled in the presence of his superior.