| effortful(adjective, great, tough, severe, difficult) |
| knotty(adjective, hard, tough, severe, rough) |
| ascending(adjective, adverb, rising, climbing) |
| demanding(adjective, hard, tough, severe, rough) |
| glitch(noun, difficulty, fault, problem, flaw) |
| labored(adjective, hard, great, tough, difficult) |
| rough(adjective, hard, great, tough, difficult) |
| severe(adjective, hard, tough, difficult, violent) |
| exhausting(adjective, hard, rough, difficult, heavy) |
| grueling(adjective, hard, tough, difficult, awkward) |
| operose(adjective, tough, severe, rough, difficult) |
| painful(hard, tough, severe, difficult, problematic) |
| rigorous(adjective, hard, tough, severe, rough) |
| rise |
| tricky(adjective, tough, difficult, complex, awkward) |
| upwards |
| wearying(adjective, tough, rough, difficult, heavy) |
| acclivity |
| ascension |
| ascent |