| complex(adjective, hard, difficult, involved, dense) |
| knotty(adjective, hard, difficult, complex, involved) |
| complicated(adjective, hard, difficult, complex, involved) |
| intricate(adjective, hard, difficult, complex, involved) |
| labyrinthine(adjective, hard, difficult, complex, involved) |
| Byzantine(adjective, hard, difficult, complex, involved) |
| involved(adjective, hard, difficult, complex, dense) |
| daedal(adjective, hard, difficult, complex) |
| elaborate(adjective, hard, difficult, complex, complicated) |
| sophisticated(adjective, hard, difficult, complex, involved) |
| arduous(adjective, hard, difficult, complex, intricate) |
| difficult(adjective, hard, complex, involved, dense) |
| hard(adjective, difficult, complex, intricate, thorny) |
| problematic(adjective, hard, difficult, complex, intricate) |
| thorny(adjective, hard, difficult, complex, involved) |
| knotted(adjective, hard, difficult, complex) |
| sinuous(adjective, hard, difficult, complex) |
| convoluted(adjective, hard, fancy, obscure, difficult) |
| baffling(adjective, difficult, awkward, tricky, complicated) |
| confusing(adjective, complex, complicated, winding) |