Synset

not to be placated or appeased or moved by entreaty
<adj.all>   freq. cnt.: 13 freq. cnt.: 8 freq. cnt.: 2 freq. cnt.: 2 freq. cnt.: 1

grim

inexorable

relentless

stern

unappeasable

unforgiving

unrelenting

sample sentences

"grim determination"
"grim necessity"
"Russia's final hour, it seemed, approached with inexorable certainty"
"relentless persecution"
"the stern demands of parenthood"