Definition of grey ghost in English English dictionary
A parking inspector, ie. person issuing tickets fining vehicles parked illegally or for too long
1998: Grey ghosts turn a blind eye — Sydney Morning Herald headline 18 July 1998.
The fish Albula neoguinaico, also called a bonefish. (Reference: Australian Fish and How to Catch Them, Richard Allan, Landsdowne Publishing, 1990, ISBN 1-86302-674-6.)
() The parking inspector sense is reputed to be a reference to grey uniforms originally worn by them, the term has remained even when those uniforms have changed.