Vicissitude
Vicissitude , noun
[Latin vicissitudo, from vicis change, turn: compare French vicissitude. See Vicarious.]
1.
Regular change or succession from one thing to another; alternation; mutual succession; interchange.
God made two great lights...
To illuminate the earth and rule the day
In their vicissitude, and rule the night.
2.
Irregular change; revolution; mutation.
3.
Changing conditions of fortune in one's life; life's ups and downs.
This man had, after many vicissitudes of fortune, sunk at last into abject and hopeless poverty.