inexorable
in-ex-o-ra-ble
adjective
Impossible to stop or prevent; relentless and unyielding, often referring to a process.
"The inexorable march of time continued."
Thesaurus
Synonyms: intransigent, inflexible, adamantine, adamant, implacable, relentless, grim, unrelenting, stern, unappeasable, unforgiving