der·vish 
(dûrvĭsh)
(dûrvĭsh)n.
1. A member of any of various Muslim ascetic orders, some of which perform whirling dances and vigorous chanting as acts of ecstatic devotion.
2. One that possesses abundant, often frenzied energy: "[She] is a dervish of unfocused energy, an accident about to happen" (Jane Gross).
[Turkish derviş, mendicant, from Persian darvēš, from Middle Persian driyōš, needy one, one who lives in holy mendicancy, from Old Iranian (Avestan) drigu-; akin to Sanskrit adhriguḥ (a divine epithet of unknown but favorable meaning) : perhaps a-, not + *dhrigu-, poor.]
dervish