(n.) The quality of being tractile; ductility.

adaptability adjustability agreeability amenability beef beefiness bendability brawn brawniness ductibility ductility extendibility extensibility facility fictility flexibility flexility flexuousness formativeness give heftiness huskiness impressionability involuntary muscle limberness litheness malleability moldability muscle muscularity musculature physique plasticity pliability pliancy receptiveness resilience responsiveness rubberiness sensibility sensitiveness sequacity sinew sinewiness sinews springiness stretch stretchability stretchiness submissiveness suppleness susceptibility tensileness tensility thew thewiness thews tolerance tone tractability tractility voluntary muscle willowiness