inextirpable

from WordNet (r) 3.0 (2006)

inextirpable
    adj 1: incapable of extermination or extirpation; "some weeds
           seem inextirpable" [syn: {inexterminable},
           {inextirpable}]

from The Collaborative International Dictionary of English v.0.48

Inextirpable \In`ex*tir"pa*ble\, a. [L. inexstirpabilis: cf. F.
   inextirpable. See {In-} not, and {Extirpate}.]
   Not capable of being extirpated or rooted out; ineradicable.
   [1913 Webster]