inconstant
Her life has been marked by inconstancy.
The novel tells a familiar story of constancy and inconstancy between lovers.
Confidence in the economy has been rising and falling with dizzying inconstancy.
Humans have long attempted to reconcile nature's inconstancies with plumbing: dams, reservoirs, canals, and pipelines to take water from wet areas to dry.

SMART Vocabulary: related words and phrases

Change and changes
adaptive evolution
adjustment
alteration
anti-evolutionism
be ahead of the curveidiom
evolutionary
evolutionism
flatten
flip-flop
fluctuation
reconversion
reformation
regime change
reinterpretation
retransformation
unspooling
unsteadily
unsteady
untick
variation

You can also find related words, phrases, and synonyms in the topics:

Relationships: infidelity
Disloyalty, betrayal & treason