| troublesome(hard, tough, difficult, negative, disapproving) |
| ugly(adjective, mean, bad, nasty, cross) |
| uncompromising(adjective, severe) |
| underlying(adjective, original, essential, fundamental, key) |
| unfavourable |
| vituperative(scornful, contemptuous, abusive, excoriating) |
| noteworthy(adjective, important, lively, outstanding, exciting) |
| refined(adjective, sharp, exact, discerning, astute) |
| accurate(adjective, honest, true, precise, real) |
| awkward(difficult, delicate, tricky, complicated, thorny) |
| detailed |
| explanatory(adjective, logical, revealing, systematic, demonstrative) |
| fateful(adjective, important, lively, significant, key) |
| nagging(adjective, hard, tough, severe, difficult) |
| prudish(adjective, severe, fastidious) |
| required(adjective, important, essential, basic, fundamental) |
| requisite(adjective, important, essential, basic, fundamental) |
| acid(adjective, severe, sharp, bitter, unkind) |
| complex(delicate, awkward, complicated) |
| conclusive(adjective, important, determined, significant, definite) |