WordWeb Online

1. Capable of existing or taking place or proving true; possible to do
   "The key to happiness is setting manageable goals";
   - accomplishable, achievable, doable, realizable, realisable [Brit]
    
2. Capable of being managed or controlled

See also: administrable, compliant, controllable, directed, dirigible [N. Amer], governable, manipulable, manipulatable, obedient, possible, steerable, tractable

Antonym: difficult