| unrelenting(adjective, mean, severe, harsh, cruel) |
| implacable(adjective, mean, severe, harsh, cruel) |
| inexorable(adjective, mean, severe, harsh, cruel) |
| relentless(adjective, mean, severe, harsh, cruel) |
| grim(adjective, mean, severe, harsh, cruel) |
| stern(adjective, mean, severe, harsh, cruel) |
| unforgiving(adjective, mean, severe, harsh, cruel) |
| insatiable(adjective, empty, gross, avid, greedy) |
| intransigent(adjective, determined, resolute, uncompromising, unshakeable) |
| unyielding(adjective, mean, severe, harsh, cruel) |
| adamant(adjective, mean, harsh, cruel, determined) |
| adamantine(adjective, determined, resolute, uncompromising, unshakeable) |
| avid(adjective, desire, empty, gross, greedy) |
| ravenous(adjective, desire, empty, gross, avid) |
| gluttonous(adjective, desire, empty, gross, avid) |
| merciless(adjective, mean, harsh, cruel, determined) |
| rapacious(adjective, desire, empty, gross, avid) |
| ruthless(adjective, mean, severe, harsh, cruel) |
| voracious(adjective, desire, empty, gross, avid) |
| quenchless(adjective, avid, greedy, wanting, rapacious) |