| fastidious(tough, problematic, trying) |
| fatiguing(adjective, tough, rough, difficult, heavy) |
| finicky(tough, problematic, trying) |
| fussy(tough, problematic, trying) |
| galling(adjective, tough, severe, painful, problematic) |
| gargantuan(adjective, tough, severe, painful, problematic) |
| grinding(adjective, tough, rough, difficult, heavy) |
| hard-earned |
| hard-fought |
| hard-won(adjective, tough, severe, painful, problematic) |
| heavy(adjective, tough, severe, rough, difficult) |
| herculean(adjective, tough, severe, rough, difficult) |
| immense(adjective, tough, severe, painful, problematic) |
| involved(adjective, tough, rough, difficult, heavy) |
| irksome(adjective, tough, rough, difficult, heavy) |
| irritating(adjective, tough, severe, painful, problematic) |
| jawbreaking |
| knotted |
| labored(adjective, tough, severe, rough, difficult) |
| merciless(adjective, tough, rough, difficult, heavy) |