R.I.P. A careless abbreviation of "requiescat in pace", attesting to indolent goodwill to the dead. According to the learned Dr. Drigge, however, the letters originally meant nothing more than "reductus in pulvis".
The Devil's Dictionary - With a Preface by the Author and a Short Biography of Ambrose Bierce (ed. Read Books Ltd, 2016) - ISBN: 9781473350182