Something so rare as to be non-existent.
He told the truth? That's rarer than rocking horse shit!
by Finbarthebad May 19, 2007
1 more definition
something rare or nonexistant (because, a roecking horse does not generate maure)
The Pictures of the encounter with the storm were like rocking horse shit.
by The Return of Light Joker April 11, 2011