vi·cis·si·tude 
(v
ĭ-s
ĭs
ĭ-t
d
′, -ty
d
′)
n.1. a. A change or variation: an economy vulnerable to the vicissitudes of the oil market.
b. A usually unforeseen change in circumstance or experience that affects one's life, especially in a trying way: the vicissitudes of childhood. See Synonyms at difficulty.
2. The quality of being changeable; mutability: the vicissitude of fortune.
[Latin vicissitūdō, from vicissim, in turn, probably from vicēs, pl. of *vix, change; see weik-2 in the Appendix of Indo-European roots.]