Dictionary.com
definitions

motu proprio

[moh-too proh-pree-oh]
noun Latin.
  1. any of certain documents issued by the pope without counsel from others.

Origin of motu proprio

literally, of one's own accord
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for motu proprio

motu proprio

noun
  1. an administrative papal bull

Word Origin for motu proprio

Latin: of his own accord
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012