unsustainable
I
adjective
baseless, controvertible, doubtful, erroneous, false, groundless, incorrect, insupportable, questionable, unauthentic, unconformable, undemonstrable, unmaintainable, unprovable, untenable, untrue, untrustworthy, unvenfiable, wrong
II
index
baseless, debatable, disputable, doubtful, dubitative, erroneous, ill-founded, illogical, insubstantial, untenable
Burton's Legal Thesaurus.
William C. Burton.
2006