a.m.

a.m. , A.M. , am or AM(indicating the time period from midnight to midday) abbreviation for (Horology) ante meridiem. Compare p.m.[Latin: before noon]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014