Synonyms:
persistent, relentless, unrelenting
Meaning: never-ceasing; "the relentless beat of the drums"
Synonyms:
brutal, unrelenting
Meaning: harsh; "the brutal summer sun"; "a brutal winter"
Synonyms:
grim, inexorable, relentless, stern, unappeasable, unforgiving, unrelenting
Meaning: not to be placated or appeased or moved by entreaty; "grim determination"; "grim necessity"; "Russia's final hour, it seemed, approached with inexorable certainty"; "relentless persecution"; "the stern demands of parenthood"