va·ga·ry 
(vāgə-rē, və-gârē)
(vāgə-rē, və-gârē)n. pl. va·ga·ries
1. An unpredictable development or change of circumstances: the vagaries of mountain weather; the vagaries of business travel.
2. An extravagant or erratic notion or action: could not explain the vagaries of his behavior.
[From Latin vagārī, to wander, from vagus, wandering.]