A & M abbreviation for 1. (Agriculture) Agricultural and Mechanical 2. (Anglicanism) Ancient and Modern (hymn book) Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014