supposable

from WordNet (r) 3.0 (2006)

supposable
    adj 1: capable of being inferred on slight grounds [syn:
           {presumable}, {supposable}, {surmisable}]

from The Collaborative International Dictionary of English v.0.48

Supposable \Sup*pos"a*ble\, a.
   Capable of being supposed, or imagined to exist; as, that is
   not a supposable case. -- {Sup*pos"a*ble*ness}, n. --
   {Sup*pos"a*bly}, adv.
   [1913 Webster]