| settled(adjective, characteristic, character, trait) |
| severe(adjective, difficulty, toughness, characteristics) |
| specific(adjective, characteristic, character, trait) |
| staying power(noun, state, characteristic, propery) |
| sticky(adjective, difficulty, toughness, characteristics) |
| stipulated(adjective, characteristic, character, trait) |
| strenuous(adjective, difficulty, toughness, characteristics) |
| taxing(adjective, difficulty, toughness, characteristics) |
| tight(adjective, difficulty, toughness, characteristics) |
| tiresome(adjective, difficulty, toughness, characteristics) |
| tough(adjective, difficulty, toughness, characteristics) |
| tricky(adjective, difficulty, toughness, characteristics) |
| troublesome(adjective, difficulty, toughness, characteristics) |
| true(adjective, characteristic, character, trait) |
| unreasonable(adjective, description, characteristics, traits) |
| upsetting(adjective, difficulty, toughness, characteristics) |
| vexing(adjective, difficulty, toughness, characteristics) |
| vigour(noun, state, characteristic, propery) |
| wearisome(adjective, difficulty, toughness, characteristics) |
| weighty(adjective, difficulty, toughness, characteristics) |