| challenging(tough, problematic, trying) |
| crucial(tough, problematic, trying) |
| demanding(tough, problematic, trying) |
| difficile(tough, problematic, trying) |
| easier said than done(expression, idiom, tough, problematic, trying) |
| effortful(tough, problematic, trying) |
| exacting(tough, problematic, trying) |
| fastidious(tough, grim, problematic, trying, troublesome) |
| finicky(tough, problematic, trying) |
| fractious(tough, grim, problematic, trying, troublesome) |
| fussy(tough, problematic, trying) |
| galling(tough, problematic, trying) |
| gargantuan(tough, problematic, trying) |
| grim(tough, problematic, trying, troublesome) |
| grueling(tough, problematic, trying) |
| hard-won(tough, problematic, trying) |
| hard to please(expression, adjective, idiom, tough, difficult) |
| heavy(tough, problematic, trying) |
| herculean(tough, problematic, trying) |
| immense(tough, problematic, trying) |