"grim determination"
"grim necessity"
"Russia's final hour, it seemed, approached with inexorable certainty"
"relentless persecution"
"the stern demands of parenthood"
"the brutal summer sun"
"a brutal winter"
"the relentless beat of the drums"
I don't think you can be very unrelenting when you see..how altered he is.
出自: C. M. Yonge
The grim, unrelenting advance of the U.S. Cavalry.
出自: N. S. Momaday
The heat outside was unrelenting.
出自: A. Lambert