| theoretical(wild, unreasonable, useless, absurd, abstract) |
| treacherous(adjective, unreliable, insecure, incalculable) |
| troublesome(adjective, unreliable, insecure, treacherous, incalculable) |
| trustless(adjective, unreliable, insecure, treacherous, incalculable) |
| truthless(adjective, unreliable, insecure, treacherous, incalculable) |
| unable(adjective, useless, unfit) |
| unapt(adjective, useless, unfit) |
| unassured(adjective, unreliable, insecure, treacherous, incalculable) |
| unattainable(adjective, wild, unreasonable, useless, absurd) |
| unbusinesslike(wild, unreasonable, useless, absurd, abstract) |
| uncertain(adjective, unreliable, insecure, treacherous, incalculable) |
| unconducive |
| undependable(adjective, unreliable, insecure, treacherous, incalculable) |
| unfeasible(adjective, wild, unreasonable, useless, absurd) |
| unfit for(adjective, useless, unfit) |
| unfitted(adjective, useless, unfit) |
| unhelpful |
| unmarketable(adjective, useless, unfit) |
| unnecessary |
| unneeded |