unrelenting
-
(s) 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
-
(s) harsh
- the brutal summer sun
- a brutal winter
-
(s) never-ceasing
- the relentless beat of the drums