"the performance of an obligation," 1530s, from Anglo-French fesance, from Old French faisance "action, deed, enactment," from faisant, present participle of faire "to make, do," from Latin facere "to make, do" (from PIE root *dhe- "to set, put").
fealty
fear
fearful
fearless
fearsome
feasance
feasibility
feasible
feasibly
feast
feat