Lewis & Short

sŭpĕrābĭlis, e, adj. [supero], that may be got over or surmounted.

  1. * I. Lit.: murus, Liv. 25, 23, 12.
  2. II. Trop., that may be overcome or subdued, conquerable, superable (very rare): non est per vim superabilis ulli, Ov. Tr. 5, 8, 27: invictos et nullis casibus superabiles Romanos praedicabant, Tac. A. 2, 25: an talis caecitas ac debilitas ope humanā superabiles forent, i. e. curable, id. H. 4, 81.