| arduous(adjective, hard, difficult, complex, painful) |
| burdensome(adjective, hard, difficult, complex, painful) |
| excruciating(adjective, characteristic, nasty, pain, painful) |
| hard-nosed(adjective, strong, hard, tough, severe) |
| hardhearted(adjective, characteristic, person, mean, hard) |
| heavy-handed(adjective, hard, difficult, complex) |
| relentless(adjective, characteristic, appearance, mean, strong) |
| serious(adjective, strong, hard, tough, severe) |
| tight(adjective, hard, difficult, complex) |
| difficult(adjective, hard, nasty, harsh, complex) |
| disturbing(adjective, mean, hard, severe, difficult) |
| fell(verb, adjective, strong, kind, severe) |
| taxing(adjective, hard, difficult, complex) |
| heinous(adjective, evil, unpleasant, awful, violent) |
| sadistic(adjective, adverb, characteristic, mean, nasty) |
| remorseless(adjective, mean, severe, harsh, violent) |
| appalling(adjective, sad, unhappy, unpleasant, awful) |
| bitter(adjective, characteristic, mean, strong, hard) |
| horrible(adjective, mean, strong, severe, evil) |
| inconsiderate(adjective, person, mean, hard, tough) |