| titanic(tough, severe, painful, problematic, trying) |
| ambitious(tough, severe, painful, problematic, trying) |
| arduous(tough, severe, painful, problematic, trying) |
| backbreaker(tough, severe, painful, problematic, trying) |
| bothersome(tough, severe, painful, problematic, trying) |
| burdensome(tough, severe, painful, problematic, trying) |
| challenging(tough, severe, painful, problematic, trying) |
| crucial(tough, severe, painful, problematic, trying) |
| demanding(tough, severe, painful, problematic, trying) |
| difficile(tough, severe, painful, problematic, trying) |
| difficult(adjective, hard, tough, problematic, trying) |
| effortful(tough, severe, painful, problematic, trying) |
| exacting(tough, severe, painful, problematic, trying) |
| galling(tough, severe, painful, problematic, trying) |
| gargantuan(tough, severe, painful, problematic, trying) |
| hard-won(tough, severe, painful, problematic, trying) |
| heavy(tough, severe, painful, problematic, trying) |
| herculean(tough, severe, painful, problematic, trying) |
| immense(tough, severe, painful, problematic, trying) |
| irritating(tough, severe, painful, problematic, trying) |