backboneless

backboneless

(ˈbækbəʊnlɪs)
adj
lacking backbone; cowardly
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
Entomologists say these invertebrates (backboneless animals) were the first creatures to fly, dating from the Carboniferous period about 360 million years ago.