A1 (?e??w?n) , A-1 or A-oneadj1. (Military) in good health; physically fit2. informal first-class; excellent3. (Nautical Terms) (of a vessel) with hull and equipment in first-class conditionCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014