Meaning

noun a variation in circumstances or fortune at different times in your life or in the development of something

noun mutability in life or nature (especially successive alternation from one condition to another)

originFrom Middle French vicissitude, from Latin vicissitūdō (“change”), from vicissim (“on the other hand, in turn”), from vicis (“change, vicissitude”), whence Portuguese vez and French fois (“time (as in "next time"), occurrence”).

Etymology from Wiktionary, CC BY-SA 3.0