Vicissitude

noun/vi-sis-i-tood/

Meaning

a change of circumstances or fortune, typically one that is unwelcome or unpleasant.

In context
Life is full of vicissitudes that test our resilience.

Remember it

From Latin vicis, 'turn' — vicissitudes are the turns of fortune life throws at you.

Use it well

Almost always plural: 'the vicissitudes of life/fortune' — a mature essay phrase for ups and downs.