Impossible to put aside or drive away: inexpugnable dislike.
[Middle English, from Old French, from Latin inexpugnābilis : in-, not; see in-1 + expugnābilis, capable of being overcome (from expugnāre : ex-, completely; see ex- + pugnāre, to fight; see impugn).] in'ex·pug·na·bil'i·ty n., in'ex·pug'na·bly adv.