Use 'ineluctable' to describe events or outcomes that are certain and cannot be changed by any means. The ineluctable march of time affects us all.
Pro Tip 2/3
Formal Tone
'Ineluctable' is formal and literary. Use it in formal writing or serious discussions, not casual conversations. His rise to power seems an ineluctable result of the political turmoil.
Pro Tip 3/3
Negative Situations
Often used for negative situations, making it seem a bit pessimistic or fatalistic. The ineluctable decline of the empire was clear to the historians.