| labyrinthian(adjective, convolution) |
| mysterious(adjective, hard, evil, obscure, heavy) |
| mystifying(adjective, hard, evil, loose, complex) |
| nice(hard, exact, full, tricky, complicated) |
| recondite(adjective, hard, fancy, evil, obscure) |
| snarled(adjective, complicated) |
| winding(verb, adjective) |
| abstract(hard, obscure, complex, tricky, complicated) |
| bewildering(adjective, hard, obscure, sophisticated, involved) |
| confounding(adjective, hard, tricky, complicated, puzzling) |
| critical(delicate, awkward, complicated) |
| exacting(adjective, tough, severe, difficult, awkward) |
| hairy(adjective, hard, tough, severe, rough) |
| prickly(thorny, spiky, spiny) |
| problematical(adjective, hard, difficult, delicate, loose) |
| showy(adjective, fancy, delicate, complex, special) |
| arcane(adjective, evil, heavy, deep, doubtful) |
| busy(adjective, complex, involved, complicated, detailed) |
| devious |
| ambiguous(adjective, complex, doubtful, vague, unclear) |