I have a lump on my foot. no pain and move able! like a cyst. what is this? and what's the cure??

Should be examined: It needs to be examined, by a doctor to determine how to proceed. Possibly X-ray or biopsy or aspiration.

Let it play out.: Without a location, it is difficult to give details. However, if it is on the top of the foot, you appraisal of "cyst" makes sense. Size and pain usually determine the action to be taken. Watch and wait is certainly acceptable, but if things about the cyst change, then have it evaluated and excised. Occasionally, these "cysts" will spontaneously rupture only to later recur.