superable (adj.) Look up superable at Dictionary.com
"surmountable," 1620s, from Latin superabilis "that may be overcome," from superare "to overcome, surmount, go over, rise above," from super "over" (from PIE root *uper "over") + -abilis (see -able). The negative formation insuperable is older and more common and superable may be a back-formation from it.