Order of the Garter n (Heraldry) the highest order of English knighthood, open to women since 1987. It consists of the sovereign, 24 knight companions, and extra members created by statute. Also called: the Garter Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014